21253275551 has 2 divisors, whose sum is σ = 21253275552. Its totient is φ = 21253275550.

The previous prime is 21253275529. The next prime is 21253275671. The reversal of 21253275551 is 15557235212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21253275551 - 2²² = 21249081247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21253275451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626637775 + 10626637776.

It is an arithmetic number, because the mean of its divisors is an integer number (10626637776).

Almost surely, 2^21253275551 is an apocalyptic number.

21253275551 is a deficient number, since it is larger than the sum of its proper divisors (1).

21253275551 is an equidigital number, since it uses as much as digits as its factorization.

21253275551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105000, while the sum is 38.

The spelling of 21253275551 in words is "twenty-one billion, two hundred fifty-three million, two hundred seventy-five thousand, five hundred fifty-one".