407776661 has 2 divisors, whose sum is σ = 407776662. Its totient is φ = 407776660.

The previous prime is 407776619. The next prime is 407776687. The reversal of 407776661 is 166677704.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 364084561 + 43692100 = 19081^2 + 6610^2 .

It is a cyclic number.

It is not a de Polignac number, because 407776661 - 2¹⁰ = 407775637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (407776561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203888330 + 203888331.

It is an arithmetic number, because the mean of its divisors is an integer number (203888331).

Almost surely, 2^407776661 is an apocalyptic number.

It is an amenable number.

407776661 is a deficient number, since it is larger than the sum of its proper divisors (1).

407776661 is an equidigital number, since it uses as much as digits as its factorization.

407776661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 296352, while the sum is 44.

The square root of 407776661 is about 20193.4806558949. The cubic root of 407776661 is about 741.5505963095.

The spelling of 407776661 in words is "four hundred seven million, seven hundred seventy-six thousand, six hundred sixty-one".