21635306442 has 16 divisors (see below), whose sum is σ = 48078458880. Its totient is φ = 7211768796.

The previous prime is 21635306417. The next prime is 21635306471. The reversal of 21635306442 is 24460353612.

21635306442 is a `hidden beast` number, since 2 + 1 + 6 + 3 + 5 + 3 + 0 + 644 + 2 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21635306397 and 21635306406.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200326858 + ... + 200326965.

It is an arithmetic number, because the mean of its divisors is an integer number (3004903680).

Almost surely, 2^21635306442 is an apocalyptic number.

21635306442 is an abundant number, since it is smaller than the sum of its proper divisors (26443152438).

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

21635306442 is a wasteful number, since it uses less digits than its factorization.

21635306442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400653834 (or 400653828 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 21635306442 in words is "twenty-one billion, six hundred thirty-five million, three hundred six thousand, four hundred forty-two".