21106307625 has 128 divisors (see below), whose sum is σ = 38886801408. Its totient is φ = 10101600000.

The previous prime is 21106307557. The next prime is 21106307647. The reversal of 21106307625 is 52670360112.

It is not a de Polignac number, because 21106307625 - 2²² = 21102113321 is a prime.

It is a super-2 number, since 2×21106307625² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 57510192 + ... + 57510558.

It is an arithmetic number, because the mean of its divisors is an integer number (303803136).

Almost surely, 2^21106307625 is an apocalyptic number.

21106307625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21106307625 is a deficient number, since it is larger than the sum of its proper divisors (17780493783).

21106307625 is a wasteful number, since it uses less digits than its factorization.

21106307625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696 (or 686 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 33.

Adding to 21106307625 its reverse (52670360112), we get a palindrome (73776667737).

The spelling of 21106307625 in words is "twenty-one billion, one hundred six million, three hundred seven thousand, six hundred twenty-five".