21153115153509 has 32 divisors (see below), whose sum is σ = 29524899959808. Its totient is φ = 13454698752000.

The previous prime is 21153115153501. The next prime is 21153115153543. The reversal of 21153115153509 is 90535151135112.

It is a happy number.

It is not a de Polignac number, because 21153115153509 - 2³ = 21153115153501 is a prime.

It is a super-2 number, since 2×21153115153509² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153115153501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15933729 + ... + 17210169.

It is an arithmetic number, because the mean of its divisors is an integer number (922653123744).

Almost surely, 2^{21153115153509} is an apocalyptic number.

It is an amenable number.

21153115153509 is a deficient number, since it is larger than the sum of its proper divisors (8371784806299).

21153115153509 is a wasteful number, since it uses less digits than its factorization.

21153115153509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1278989.

The product of its (nonzero) digits is 101250, while the sum is 42.

The spelling of 21153115153509 in words is "twenty-one trillion, one hundred fifty-three billion, one hundred fifteen million, one hundred fifty-three thousand, five hundred nine".