21307864842 has 48 divisors (see below), whose sum is σ = 50586018912. Its totient is φ = 6428470560.

The previous prime is 21307864841. The next prime is 21307864901. The reversal of 21307864842 is 24846870312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21307864841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 192093 + ... + 281984.

It is an arithmetic number, because the mean of its divisors is an integer number (1053875394).

Almost surely, 2^21307864842 is an apocalyptic number.

21307864842 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21307864842 is an abundant number, since it is smaller than the sum of its proper divisors (29278154070).

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

21307864842 is a wasteful number, since it uses less digits than its factorization.

21307864842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474323 (or 474320 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The spelling of 21307864842 in words is "twenty-one billion, three hundred seven million, eight hundred sixty-four thousand, eight hundred forty-two".