21512200405104 has 40 divisors (see below), whose sum is σ = 61747982645520. Its totient is φ = 7170733468224.

The previous prime is 21512200404997. The next prime is 21512200405121. The reversal of 21512200405104 is 40150400221512.

It is a happy number.

21512200405104 is a `hidden beast` number, since 2 + 1 + 51 + 2 + 200 + 405 + 1 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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, 24898379667 + ... + 24898380530.

It is an arithmetic number, because the mean of its divisors is an integer number (1543699566138).

Almost surely, 2^{21512200405104} is an apocalyptic number.

21512200405104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21512200405104 is an abundant number, since it is smaller than the sum of its proper divisors (40235782240416).

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

21512200405104 is a wasteful number, since it uses less digits than its factorization.

21512200405104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49796760214 (or 49796760202 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 21512200405104 its reverse (40150400221512), we get a palindrome (61662600626616).

The spelling of 21512200405104 in words is "twenty-one trillion, five hundred twelve billion, two hundred million, four hundred five thousand, one hundred four".