16905829621 has 2 divisors, whose sum is σ = 16905829622. Its totient is φ = 16905829620.

The previous prime is 16905829607. The next prime is 16905829631. The reversal of 16905829621 is 12692850961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16496576721 + 409252900 = 128439^2 + 20230^2 .

It is a cyclic number.

It is not a de Polignac number, because 16905829621 - 2²⁷ = 16771611893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16905829631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8452914810 + 8452914811.

It is an arithmetic number, because the mean of its divisors is an integer number (8452914811).

Almost surely, 2^16905829621 is an apocalyptic number.

It is an amenable number.

16905829621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16905829621 is an equidigital number, since it uses as much as digits as its factorization.

16905829621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 49.

The spelling of 16905829621 in words is "sixteen billion, nine hundred five million, eight hundred twenty-nine thousand, six hundred twenty-one".