646941377 has 2 divisors, whose sum is σ = 646941378. Its totient is φ = 646941376.

The previous prime is 646941353. The next prime is 646941389. The reversal of 646941377 is 773149646.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390813361 + 256128016 = 19769^2 + 16004^2 .

It is a cyclic number.

It is not a de Polignac number, because 646941377 - 2⁸ = 646941121 is a prime.

It is a super-2 number, since 2×646941377² = 837066290549312258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (646949377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323470688 + 323470689.

It is an arithmetic number, because the mean of its divisors is an integer number (323470689).

Almost surely, 2^646941377 is an apocalyptic number.

It is an amenable number.

646941377 is a deficient number, since it is larger than the sum of its proper divisors (1).

646941377 is an equidigital number, since it uses as much as digits as its factorization.

646941377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 47.

The square root of 646941377 is about 25435.0423038768. The cubic root of 646941377 is about 864.8782512109.

The spelling of 646941377 in words is "six hundred forty-six million, nine hundred forty-one thousand, three hundred seventy-seven".