21247125524 has 12 divisors (see below), whose sum is σ = 37653134400. Its totient is φ = 10489087128.

The previous prime is 21247125503. The next prime is 21247125553. The reversal of 21247125524 is 42552174212.

It is a super-2 number, since 2×21247125524² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33618554 + ... + 33619185.

It is an arithmetic number, because the mean of its divisors is an integer number (3137761200).

Almost surely, 2^21247125524 is an apocalyptic number.

It is an amenable number.

21247125524 is a deficient number, since it is larger than the sum of its proper divisors (16406008876).

21247125524 is a wasteful number, since it uses less digits than its factorization.

21247125524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67237822 (or 67237820 counting only the distinct ones).

The product of its digits is 44800, while the sum is 35.

Adding to 21247125524 its reverse (42552174212), we get a palindrome (63799299736).

The spelling of 21247125524 in words is "twenty-one billion, two hundred forty-seven million, one hundred twenty-five thousand, five hundred twenty-four".