21503907942 has 32 divisors (see below), whose sum is σ = 46926172800. Its totient is φ = 6515147520.

The previous prime is 21503907839. The next prime is 21503907991. The reversal of 21503907942 is 24970930512.

It is a junction number, because it is equal to n+sod(n) for n = 21503907894 and 21503907903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 376809 + ... + 430107.

It is an arithmetic number, because the mean of its divisors is an integer number (1466442900).

Almost surely, 2^21503907942 is an apocalyptic number.

21503907942 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21503907942 is an abundant number, since it is smaller than the sum of its proper divisors (25422264858).

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

21503907942 is a wasteful number, since it uses less digits than its factorization.

21503907942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59428.

The product of its (nonzero) digits is 136080, while the sum is 42.

The spelling of 21503907942 in words is "twenty-one billion, five hundred three million, nine hundred seven thousand, nine hundred forty-two".