21153335661654 has 32 divisors (see below), whose sum is σ = 48350739667200. Its totient is φ = 6043777919712.

The previous prime is 21153335661641. The next prime is 21153335661659. The reversal of 21153335661654 is 45616653335112.

It is a super-2 number, since 2×21153335661654² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21153335661597 and 21153335661606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153335661659) 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, 7263777 + ... + 9750339.

It is an arithmetic number, because the mean of its divisors is an integer number (1510960614600).

Almost surely, 2^{21153335661654} is an apocalyptic number.

21153335661654 is an abundant number, since it is smaller than the sum of its proper divisors (27197404005546).

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

21153335661654 is a wasteful number, since it uses less digits than its factorization.

21153335661654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689124.

The product of its digits is 5832000, while the sum is 51.

Adding to 21153335661654 its reverse (45616653335112), we get a palindrome (66769988996766).

The spelling of 21153335661654 in words is "twenty-one trillion, one hundred fifty-three billion, three hundred thirty-five million, six hundred sixty-one thousand, six hundred fifty-four".