645954911 has 4 divisors (see below), whose sum is σ = 738234192. Its totient is φ = 553675632.

The previous prime is 645954889. The next prime is 645954919. The reversal of 645954911 is 119459546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645954911 - 2⁶ = 645954847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645954919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46139630 + ... + 46139643.

It is an arithmetic number, because the mean of its divisors is an integer number (184558548).

Almost surely, 2^645954911 is an apocalyptic number.

645954911 is a deficient number, since it is larger than the sum of its proper divisors (92279281).

645954911 is an equidigital number, since it uses as much as digits as its factorization.

645954911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92279280.

The product of its digits is 194400, while the sum is 44.

The square root of 645954911 is about 25415.6430373107. The cubic root of 645954911 is about 864.4384344409.

The spelling of 645954911 in words is "six hundred forty-five million, nine hundred fifty-four thousand, nine hundred eleven".