21564206046 has 40 divisors (see below), whose sum is σ = 48700312320. Its totient is φ = 7131462912.

The previous prime is 21564206039. The next prime is 21564206063. The reversal of 21564206046 is 64060246512.

21564206046 is a `hidden beast` number, since 2 + 1 + 5 + 6 + 42 + 0 + 604 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21564206046.

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 19 ways as a sum of consecutive naturals, for example, 503491 + ... + 544638.

It is an arithmetic number, because the mean of its divisors is an integer number (1217507808).

Almost surely, 2^21564206046 is an apocalyptic number.

21564206046 is an abundant number, since it is smaller than the sum of its proper divisors (27136106274).

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

21564206046 is a wasteful number, since it uses less digits than its factorization.

21564206046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048270 (or 1048261 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 21564206046 in words is "twenty-one billion, five hundred sixty-four million, two hundred six thousand, forty-six".