21568627451 has 4 divisors (see below), whose sum is σ = 24649859952. Its totient is φ = 18487394952.

The previous prime is 21568627411. The next prime is 21568627517. The reversal of 21568627451 is 15472686512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21568627451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21568627396 and 21568627405.

It is not an unprimeable number, because it can be changed into a prime (21568627411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1540616240 + ... + 1540616253.

It is an arithmetic number, because the mean of its divisors is an integer number (6162464988).

Almost surely, 2^21568627451 is an apocalyptic number.

21568627451 is a deficient number, since it is larger than the sum of its proper divisors (3081232501).

21568627451 is an equidigital number, since it uses as much as digits as its factorization.

21568627451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3081232500.

The product of its digits is 806400, while the sum is 47.

The spelling of 21568627451 in words is "twenty-one billion, five hundred sixty-eight million, six hundred twenty-seven thousand, four hundred fifty-one".