21411551025 has 72 divisors (see below), whose sum is σ = 38915243640. Its totient is φ = 11252229120.

The previous prime is 21411550999. The next prime is 21411551027. The reversal of 21411551025 is 52015511412.

It is a happy number.

21411551025 is a `hidden beast` number, since 2 + 14 + 115 + 510 + 25 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 7487787024 + 13923764001 = 86532^2 + 117999^2 .

It is not a de Polignac number, because 21411551025 - 2¹⁰ = 21411550001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21411551025.

It is not an unprimeable number, because it can be changed into a prime (21411551027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6346239 + ... + 6349611.

It is an arithmetic number, because the mean of its divisors is an integer number (540489495).

Almost surely, 2^21411551025 is an apocalyptic number.

21411551025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21411551025 is a deficient number, since it is larger than the sum of its proper divisors (17503692615).

21411551025 is a wasteful number, since it uses less digits than its factorization.

21411551025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3795 (or 3787 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The spelling of 21411551025 in words is "twenty-one billion, four hundred eleven million, five hundred fifty-one thousand, twenty-five".