645730761431 has 24 divisors (see below), whose sum is σ = 812726913024. Its totient is φ = 501554805840.

The previous prime is 645730761427. The next prime is 645730761439. The reversal of 645730761431 is 134167037546.

It is not a de Polignac number, because 645730761431 - 2² = 645730761427 is a prime.

It is a super-2 number, since 2×645730761431² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645730761439) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5496935 + ... + 5613176.

It is an arithmetic number, because the mean of its divisors is an integer number (33863621376).

Almost surely, 2^645730761431 is an apocalyptic number.

645730761431 is a deficient number, since it is larger than the sum of its proper divisors (166996151593).

645730761431 is a wasteful number, since it uses less digits than its factorization.

645730761431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11110179 (or 11110160 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 47.

Adding to 645730761431 its reverse (134167037546), we get a palindrome (779897798977).

The spelling of 645730761431 in words is "six hundred forty-five billion, seven hundred thirty million, seven hundred sixty-one thousand, four hundred thirty-one".