21154511036653 has 4 divisors (see below), whose sum is σ = 21229261959328. Its totient is φ = 21079760113980.

The previous prime is 21154511036611. The next prime is 21154511036657. The reversal of 21154511036653 is 35663011545112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21154511036653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154511036657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37375460913 + ... + 37375461478.

It is an arithmetic number, because the mean of its divisors is an integer number (5307315489832).

Almost surely, 2^{21154511036653} is an apocalyptic number.

It is an amenable number.

21154511036653 is a deficient number, since it is larger than the sum of its proper divisors (74750922675).

21154511036653 is an equidigital number, since it uses as much as digits as its factorization.

21154511036653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74750922674.

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 21154511036653 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred eleven million, thirty-six thousand, six hundred fifty-three".