645133787 has 2 divisors, whose sum is σ = 645133788. Its totient is φ = 645133786.

The previous prime is 645133751. The next prime is 645133807. The reversal of 645133787 is 787331546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645133787 is a prime.

It is a super-2 number, since 2×645133787² = 832395206257922738, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (645133717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322566893 + 322566894.

It is an arithmetic number, because the mean of its divisors is an integer number (322566894).

Almost surely, 2^645133787 is an apocalyptic number.

645133787 is a deficient number, since it is larger than the sum of its proper divisors (1).

645133787 is an equidigital number, since it uses as much as digits as its factorization.

645133787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 423360, while the sum is 44.

The square root of 645133787 is about 25399.4839908215. The cubic root of 645133787 is about 864.0719939401.

The spelling of 645133787 in words is "six hundred forty-five million, one hundred thirty-three thousand, seven hundred eighty-seven".