21121153134625 has 32 divisors (see below), whose sum is σ = 27921410034336. Its totient is φ = 15896336435200.

The previous prime is 21121153134611. The next prime is 21121153134637. The reversal of 21121153134625 is 52643135112112.

It can be written as a sum of positive squares in 16 ways, for example, as 12688442423056 + 8432710711569 = 3562084^2 + 2903913^2 .

It is not a de Polignac number, because 21121153134625 - 2²⁵ = 21121119580193 is a prime.

It is a super-2 number, since 2×21121153134625² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3008367 + ... + 7161883.

It is an arithmetic number, because the mean of its divisors is an integer number (872544063573).

Almost surely, 2^{21121153134625} is an apocalyptic number.

21121153134625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21121153134625 is a deficient number, since it is larger than the sum of its proper divisors (6800256899711).

21121153134625 is a wasteful number, since it uses less digits than its factorization.

21121153134625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4155942 (or 4155932 counting only the distinct ones).

The product of its digits is 43200, while the sum is 37.

Adding to 21121153134625 its reverse (52643135112112), we get a palindrome (73764288246737).

The spelling of 21121153134625 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred fifty-three million, one hundred thirty-four thousand, six hundred twenty-five".