1275821897 has 4 divisors (see below), whose sum is σ = 1458082176. Its totient is φ = 1093561620.

The previous prime is 1275821863. The next prime is 1275821903. The reversal of 1275821897 is 7981285721.

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 a cyclic number.

It is not a de Polignac number, because 1275821897 - 2¹² = 1275817801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1275421897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91130129 + ... + 91130142.

It is an arithmetic number, because the mean of its divisors is an integer number (364520544).

Almost surely, 2^1275821897 is an apocalyptic number.

It is an amenable number.

1275821897 is a deficient number, since it is larger than the sum of its proper divisors (182260279).

1275821897 is an equidigital number, since it uses as much as digits as its factorization.

1275821897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182260278.

The product of its digits is 564480, while the sum is 50.

The square root of 1275821897 is about 35718.6491485890. The cubic root of 1275821897 is about 1084.5843926288.

The spelling of 1275821897 in words is "one billion, two hundred seventy-five million, eight hundred twenty-one thousand, eight hundred ninety-seven".