21124631925 has 60 divisors (see below), whose sum is σ = 40084671396. Its totient is φ = 10991635200.

The previous prime is 21124631923. The next prime is 21124631977. The reversal of 21124631925 is 52913642112.

21124631925 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 463 + 192 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 8415677169 + 12708954756 = 91737^2 + 112734^2 .

It is not a de Polignac number, because 21124631925 - 2¹ = 21124631923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21124631925.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124631923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 44194 + ... + 210243.

Almost surely, 2^21124631925 is an apocalyptic number.

21124631925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21124631925 is a deficient number, since it is larger than the sum of its proper divisors (18960039471).

21124631925 is a wasteful number, since it uses less digits than its factorization.

21124631925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254500 (or 254486 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The spelling of 21124631925 in words is "twenty-one billion, one hundred twenty-four million, six hundred thirty-one thousand, nine hundred twenty-five".