21918295951 has 2 divisors, whose sum is σ = 21918295952. Its totient is φ = 21918295950.

The previous prime is 21918295943. The next prime is 21918295963. The reversal of 21918295951 is 15959281912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21918295951 - 2³ = 21918295943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21918295151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10959147975 + 10959147976.

It is an arithmetic number, because the mean of its divisors is an integer number (10959147976).

Almost surely, 2^21918295951 is an apocalyptic number.

21918295951 is a deficient number, since it is larger than the sum of its proper divisors (1).

21918295951 is an equidigital number, since it uses as much as digits as its factorization.

21918295951 is an evil number, because the sum of its binary digits is even.

The product of its digits is 583200, while the sum is 52.

The spelling of 21918295951 in words is "twenty-one billion, nine hundred eighteen million, two hundred ninety-five thousand, nine hundred fifty-one".