21390255941 has 4 divisors (see below), whose sum is σ = 21647969952. Its totient is φ = 21132541932.

The previous prime is 21390255937. The next prime is 21390255947. The reversal of 21390255941 is 14955209312.

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 21390255941 - 2² = 21390255937 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21390255947) 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, 128856881 + ... + 128857046.

It is an arithmetic number, because the mean of its divisors is an integer number (5411992488).

Almost surely, 2^21390255941 is an apocalyptic number.

It is an amenable number.

21390255941 is a deficient number, since it is larger than the sum of its proper divisors (257714011).

21390255941 is an equidigital number, since it uses as much as digits as its factorization.

21390255941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257714010.

The product of its (nonzero) digits is 97200, while the sum is 41.

The spelling of 21390255941 in words is "twenty-one billion, three hundred ninety million, two hundred fifty-five thousand, nine hundred forty-one".