21515050251153 has 12 divisors (see below), whose sum is σ = 31098166078980. Its totient is φ = 14333733939456.

The previous prime is 21515050251083. The next prime is 21515050251179. The reversal of 21515050251153 is 35115205051512.

21515050251153 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 50 + 502 + 51 + 1 + 53 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12122492537169 + 9392557713984 = 3481737^2 + 3064728^2 .

It is not a de Polignac number, because 21515050251153 - 2¹² = 21515050247057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21515050251053) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 802727076 + ... + 802753877.

It is an arithmetic number, because the mean of its divisors is an integer number (2591513839915).

Almost surely, 2^{21515050251153} is an apocalyptic number.

It is an amenable number.

21515050251153 is a deficient number, since it is larger than the sum of its proper divisors (9583115827827).

21515050251153 is a wasteful number, since it uses less digits than its factorization.

21515050251153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1605482448 (or 1605482445 counting only the distinct ones).

The product of its (nonzero) digits is 37500, while the sum is 36.

The spelling of 21515050251153 in words is "twenty-one trillion, five hundred fifteen billion, fifty million, two hundred fifty-one thousand, one hundred fifty-three".