21292087640 has 32 divisors (see below), whose sum is σ = 47940299280. Its totient is φ = 8510950272.

The previous prime is 21292087573. The next prime is 21292087657. The reversal of 21292087640 is 4678029212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125054 + ... + 241293.

Almost surely, 2^21292087640 is an apocalyptic number.

21292087640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21292087640 is an abundant number, since it is smaller than the sum of its proper divisors (26648211640).

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

21292087640 is a wasteful number, since it uses less digits than its factorization.

21292087640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367811 (or 367807 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 21292087640 in words is "twenty-one billion, two hundred ninety-two million, eighty-seven thousand, six hundred forty".