405779669 has 2 divisors, whose sum is σ = 405779670. Its totient is φ = 405779668.

The previous prime is 405779651. The next prime is 405779707. The reversal of 405779669 is 966977504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 405498769 + 280900 = 20137^2 + 530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405779669 is a prime.

It is a super-2 number, since 2×405779669² = 329314279547499122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 405779669.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405779609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202889834 + 202889835.

It is an arithmetic number, because the mean of its divisors is an integer number (202889835).

Almost surely, 2^405779669 is an apocalyptic number.

It is an amenable number.

405779669 is a deficient number, since it is larger than the sum of its proper divisors (1).

405779669 is an equidigital number, since it uses as much as digits as its factorization.

405779669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2857680, while the sum is 53.

The square root of 405779669 is about 20143.9735156696. The cubic root of 405779669 is about 740.3380905793.

The spelling of 405779669 in words is "four hundred five million, seven hundred seventy-nine thousand, six hundred sixty-nine".