21858612051 has 16 divisors (see below), whose sum is σ = 30462142464. Its totient is φ = 13915834944.

The previous prime is 21858612037. The next prime is 21858612067. The reversal of 21858612051 is 15021685812.

It is not a de Polignac number, because 21858612051 - 2⁹ = 21858611539 is a prime.

It is a super-2 number, since 2×21858612051² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21858612011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 219066 + ... + 302831.

It is an arithmetic number, because the mean of its divisors is an integer number (1903883904).

Almost surely, 2^21858612051 is an apocalyptic number.

21858612051 is a deficient number, since it is larger than the sum of its proper divisors (8603530413).

21858612051 is a wasteful number, since it uses less digits than its factorization.

21858612051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522530.

The product of its (nonzero) digits is 38400, while the sum is 39.

The spelling of 21858612051 in words is "twenty-one billion, eight hundred fifty-eight million, six hundred twelve thousand, fifty-one".