645379277 has 2 divisors, whose sum is σ = 645379278. Its totient is φ = 645379276.

The previous prime is 645379249. The next prime is 645379283. The reversal of 645379277 is 772973546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542843401 + 102535876 = 23299^2 + 10126^2 .

It is a cyclic number.

It is not a de Polignac number, because 645379277 - 2¹⁶ = 645313741 is a prime.

It is a super-2 number, since 2×645379277² = 833028822362085458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645375277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322689638 + 322689639.

It is an arithmetic number, because the mean of its divisors is an integer number (322689639).

Almost surely, 2^645379277 is an apocalyptic number.

It is an amenable number.

645379277 is a deficient number, since it is larger than the sum of its proper divisors (1).

645379277 is an equidigital number, since it uses as much as digits as its factorization.

645379277 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2222640, while the sum is 50.

The square root of 645379277 is about 25404.3161096692. The cubic root of 645379277 is about 864.1815805809.

The spelling of 645379277 in words is "six hundred forty-five million, three hundred seventy-nine thousand, two hundred seventy-seven".