21858602420 has 48 divisors (see below), whose sum is σ = 46095875280. Its totient is φ = 8706794496.

The previous prime is 21858602393. The next prime is 21858602429. The reversal of 21858602420 is 2420685812.

It can be written as a sum of positive squares in 8 ways, for example, as 37994896 + 21820607524 = 6164^2 + 147718^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21858602429) 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, 5700824 + ... + 5704656.

It is an arithmetic number, because the mean of its divisors is an integer number (960330735).

Almost surely, 2^21858602420 is an apocalyptic number.

21858602420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21858602420 is an abundant number, since it is smaller than the sum of its proper divisors (24237272860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21858602420 is a wasteful number, since it uses less digits than its factorization.

21858602420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4964 (or 4962 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 38.

The spelling of 21858602420 in words is "twenty-one billion, eight hundred fifty-eight million, six hundred two thousand, four hundred twenty".