21858025064 has 8 divisors (see below), whose sum is σ = 40983797010. Its totient is φ = 10929012528.

The previous prime is 21858025027. The next prime is 21858025069. The reversal of 21858025064 is 46052085812.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20781528964 + 1076496100 = 144158^2 + 32810^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21858025069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1366126559 + ... + 1366126574.

Almost surely, 2^21858025064 is an apocalyptic number.

It is an amenable number.

21858025064 is a deficient number, since it is larger than the sum of its proper divisors (19125771946).

21858025064 is a wasteful number, since it uses less digits than its factorization.

21858025064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2732253139 (or 2732253135 counting only the distinct ones).

The product of its (nonzero) digits is 153600, while the sum is 41.

The spelling of 21858025064 in words is "twenty-one billion, eight hundred fifty-eight million, twenty-five thousand, sixty-four".