21885038551 has 2 divisors, whose sum is σ = 21885038552. Its totient is φ = 21885038550.

The previous prime is 21885038531. The next prime is 21885038579. The reversal of 21885038551 is 15583058812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21885038551 - 2¹⁵ = 21885005783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21885038531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10942519275 + 10942519276.

It is an arithmetic number, because the mean of its divisors is an integer number (10942519276).

Almost surely, 2^21885038551 is an apocalyptic number.

21885038551 is a deficient number, since it is larger than the sum of its proper divisors (1).

21885038551 is an equidigital number, since it uses as much as digits as its factorization.

21885038551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384000, while the sum is 46.

The spelling of 21885038551 in words is "twenty-one billion, eight hundred eighty-five million, thirty-eight thousand, five hundred fifty-one".