21121012013544 has 48 divisors (see below), whose sum is σ = 57493110151620. Its totient is φ = 7004599580160.

The previous prime is 21121012013483. The next prime is 21121012013567. The reversal of 21121012013544 is 44531021012112.

21121012013544 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 101 + 2 + 0 + 13 + 544 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 14666678684100 + 6454333329444 = 3829710^2 + 2540538^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 744522337 + ... + 744550704.

Almost surely, 2^{21121012013544} is an apocalyptic number.

21121012013544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21121012013544 is an abundant number, since it is smaller than the sum of its proper divisors (36372098138076).

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

21121012013544 is a wasteful number, since it uses less digits than its factorization.

21121012013544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1489073250 (or 1489073243 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

Adding to 21121012013544 its reverse (44531021012112), we get a palindrome (65652033025656).

The spelling of 21121012013544 in words is "twenty-one trillion, one hundred twenty-one billion, twelve million, thirteen thousand, five hundred forty-four".