21653013501 has 16 divisors (see below), whose sum is σ = 36661187200. Its totient is φ = 12373150464.

The previous prime is 21653013493. The next prime is 21653013539. The reversal of 21653013501 is 10531035612.

21653013501 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 301 + 350 + 1 = 666.

It is not a de Polignac number, because 21653013501 - 2³ = 21653013493 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21653013401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57282916 + ... + 57283293.

It is an arithmetic number, because the mean of its divisors is an integer number (2291324200).

Almost surely, 2^21653013501 is an apocalyptic number.

21653013501 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21653013501 is a deficient number, since it is larger than the sum of its proper divisors (15008173699).

21653013501 is a wasteful number, since it uses less digits than its factorization.

21653013501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114566225 (or 114566219 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The spelling of 21653013501 in words is "twenty-one billion, six hundred fifty-three million, thirteen thousand, five hundred one".