5127121981 has 4 divisors (see below), whose sum is σ = 5350040352. Its totient is φ = 4904203612.

The previous prime is 5127121973. The next prime is 5127122017. The reversal of 5127121981 is 1891217215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 5127121981 - 2³ = 5127121973 is a prime.

It is a super-2 number, since 2×5127121981² = 52574759616106728722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 5127121981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5127121921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111459151 + ... + 111459196.

It is an arithmetic number, because the mean of its divisors is an integer number (1337510088).

Almost surely, 2^5127121981 is an apocalyptic number.

It is an amenable number.

5127121981 is a deficient number, since it is larger than the sum of its proper divisors (222918371).

5127121981 is a wasteful number, since it uses less digits than its factorization.

5127121981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222918370.

The product of its digits is 10080, while the sum is 37.

The square root of 5127121981 is about 71603.9243407790. The cubic root of 5127121981 is about 1724.3465402511.

The spelling of 5127121981 in words is "five billion, one hundred twenty-seven million, one hundred twenty-one thousand, nine hundred eighty-one".