405680557 has 2 divisors, whose sum is σ = 405680558. Its totient is φ = 405680556.

The previous prime is 405680531. The next prime is 405680591. The reversal of 405680557 is 755086504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392277636 + 13402921 = 19806^2 + 3661^2 .

It is a cyclic number.

It is not a de Polignac number, because 405680557 - 2¹⁵ = 405647789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405680657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202840278 + 202840279.

It is an arithmetic number, because the mean of its divisors is an integer number (202840279).

Almost surely, 2^405680557 is an apocalyptic number.

It is an amenable number.

405680557 is a deficient number, since it is larger than the sum of its proper divisors (1).

405680557 is an equidigital number, since it uses as much as digits as its factorization.

405680557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168000, while the sum is 40.

The square root of 405680557 is about 20141.5132748262. The cubic root of 405680557 is about 740.2778096195.

The spelling of 405680557 in words is "four hundred five million, six hundred eighty thousand, five hundred fifty-seven".