21437907426 has 48 divisors (see below), whose sum is σ = 52964251704. Its totient is φ = 6208261632.

The previous prime is 21437907373. The next prime is 21437907437. The reversal of 21437907426 is 62470973412.

21437907426 is a `hidden beast` number, since 214 + 3 + 7 + 9 + 0 + 7 + 426 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 12862962225 + 8574945201 = 113415^2 + 92601^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2690581 + ... + 2698536.

Almost surely, 2^21437907426 is an apocalyptic number.

21437907426 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21437907426 is an abundant number, since it is smaller than the sum of its proper divisors (31526344278).

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

21437907426 is a wasteful number, since it uses less digits than its factorization.

21437907426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5389155 (or 5389152 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 21437907426 in words is "twenty-one billion, four hundred thirty-seven million, nine hundred seven thousand, four hundred twenty-six".