21306625406651 has 8 divisors (see below), whose sum is σ = 23736824060880. Its totient is φ = 18989459248032.

The previous prime is 21306625406621. The next prime is 21306625406657. The reversal of 21306625406651 is 15660452660312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21306625406651 - 2²² = 21306621212347 is a prime.

It is a super-2 number, since 2×21306625406651² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21306625406596 and 21306625406605.

It is not an unprimeable number, because it can be changed into a prime (21306625406657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28258123505 + ... + 28258124258.

It is an arithmetic number, because the mean of its divisors is an integer number (2967103007610).

Almost surely, 2^{21306625406651} is an apocalyptic number.

21306625406651 is a deficient number, since it is larger than the sum of its proper divisors (2430198654229).

21306625406651 is a wasteful number, since it uses less digits than its factorization.

21306625406651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56516247805.

The product of its (nonzero) digits is 1555200, while the sum is 47.

The spelling of 21306625406651 in words is "twenty-one trillion, three hundred six billion, six hundred twenty-five million, four hundred six thousand, six hundred fifty-one".