855513097921 has 4 divisors (see below), whose sum is σ = 863819050432. Its totient is φ = 847207145412.

The previous prime is 855513097913. The next prime is 855513097931. The reversal of 855513097921 is 129790315558.

It is a happy number.

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 855513097921 - 2³ = 855513097913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855513097931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4152976101 + ... + 4152976306.

It is an arithmetic number, because the mean of its divisors is an integer number (215954762608).

Almost surely, 2^855513097921 is an apocalyptic number.

It is an amenable number.

855513097921 is a deficient number, since it is larger than the sum of its proper divisors (8305952511).

855513097921 is a wasteful number, since it uses less digits than its factorization.

855513097921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8305952510.

The product of its (nonzero) digits is 3402000, while the sum is 55.

The spelling of 855513097921 in words is "eight hundred fifty-five billion, five hundred thirteen million, ninety-seven thousand, nine hundred twenty-one".