16415351921 has 2 divisors, whose sum is σ = 16415351922. Its totient is φ = 16415351920.

The previous prime is 16415351899. The next prime is 16415351977. The reversal of 16415351921 is 12915351461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16254975025 + 160376896 = 127495^2 + 12664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16415351921 is a prime.

It is not a weakly prime, because it can be changed into another prime (16415356921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8207675960 + 8207675961.

It is an arithmetic number, because the mean of its divisors is an integer number (8207675961).

Almost surely, 2^16415351921 is an apocalyptic number.

It is an amenable number.

16415351921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16415351921 is an equidigital number, since it uses as much as digits as its factorization.

16415351921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 38.

The spelling of 16415351921 in words is "sixteen billion, four hundred fifteen million, three hundred fifty-one thousand, nine hundred twenty-one".