21155030124125 has 8 divisors (see below), whose sum is σ = 26401477595064. Its totient is φ = 16924024099200.

The previous prime is 21155030124113. The next prime is 21155030124161. The reversal of 21155030124125 is 52142103055112.

It can be written as a sum of positive squares in 4 ways, for example, as 669865313209 + 20485164810916 = 818453^2 + 4526054^2 .

It is not a de Polignac number, because 21155030124125 - 2⁶ = 21155030124061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21155030124091 and 21155030124100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84620120372 + ... + 84620120621.

It is an arithmetic number, because the mean of its divisors is an integer number (3300184699383).

Almost surely, 2^{21155030124125} is an apocalyptic number.

21155030124125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21155030124125 is a deficient number, since it is larger than the sum of its proper divisors (5246447470939).

21155030124125 is an equidigital number, since it uses as much as digits as its factorization.

21155030124125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169240241008 (or 169240240998 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 32.

Adding to 21155030124125 its reverse (52142103055112), we get a palindrome (73297133179237).

The spelling of 21155030124125 in words is "twenty-one trillion, one hundred fifty-five billion, thirty million, one hundred twenty-four thousand, one hundred twenty-five".