21581461854502 has 32 divisors (see below), whose sum is σ = 35785906168320. Its totient is φ = 9679838825280.

The previous prime is 21581461854457. The next prime is 21581461854527. The reversal of 21581461854502 is 20545816418512.

It is a self number, because there is not a number n which added to its sum of digits gives 21581461854502.

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, 20935002 + ... + 21941677.

It is an arithmetic number, because the mean of its divisors is an integer number (1118309567760).

Almost surely, 2^{21581461854502} is an apocalyptic number.

21581461854502 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21581461854502 is a deficient number, since it is larger than the sum of its proper divisors (14204444313818).

21581461854502 is a wasteful number, since it uses less digits than its factorization.

21581461854502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42876996.

The product of its (nonzero) digits is 3072000, while the sum is 52.

The spelling of 21581461854502 in words is "twenty-one trillion, five hundred eighty-one billion, four hundred sixty-one million, eight hundred fifty-four thousand, five hundred two".