20513633221536 has 96 divisors (see below), whose sum is σ = 66274815051648. Its totient is φ = 5410188979200.

The previous prime is 20513633221511. The next prime is 20513633221553. The reversal of 20513633221536 is 63512233631502.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 1174077415 + ... + 1174094886.

It is an arithmetic number, because the mean of its divisors is an integer number (690362656788).

Almost surely, 2^{20513633221536} is an apocalyptic number.

20513633221536 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20513633221536 is an abundant number, since it is smaller than the sum of its proper divisors (45761181830112).

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

20513633221536 is a wasteful number, since it uses less digits than its factorization.

20513633221536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348172334 (or 2348172326 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 42.

The spelling of 20513633221536 in words is "twenty trillion, five hundred thirteen billion, six hundred thirty-three million, two hundred twenty-one thousand, five hundred thirty-six".