21051200657 has 8 divisors (see below), whose sum is σ = 22291656192. Its totient is φ = 19810984000.

The previous prime is 21051200627. The next prime is 21051200713. The reversal of 21051200657 is 75600215012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21051200657 - 2¹⁰ = 21051199633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21051200617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141032 + ... + 248982.

It is an arithmetic number, because the mean of its divisors is an integer number (2786457024).

Almost surely, 2^21051200657 is an apocalyptic number.

It is an amenable number.

21051200657 is a deficient number, since it is larger than the sum of its proper divisors (1240455535).

21051200657 is a wasteful number, since it uses less digits than its factorization.

21051200657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119439.

The product of its (nonzero) digits is 4200, while the sum is 29.

Adding to 21051200657 its reverse (75600215012), we get a palindrome (96651415669).

The spelling of 21051200657 in words is "twenty-one billion, fifty-one million, two hundred thousand, six hundred fifty-seven".