640460401 has 4 divisors (see below), whose sum is σ = 731954752. Its totient is φ = 548966052.

The previous prime is 640460371. The next prime is 640460407. The reversal of 640460401 is 104064046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640460401 - 2⁹ = 640459889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640460407) 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, 45747165 + ... + 45747178.

It is an arithmetic number, because the mean of its divisors is an integer number (182988688).

Almost surely, 2^640460401 is an apocalyptic number.

It is an amenable number.

640460401 is a deficient number, since it is larger than the sum of its proper divisors (91494351).

640460401 is an equidigital number, since it uses as much as digits as its factorization.

640460401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91494350.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 640460401 is about 25307.3191191797. The cubic root of 640460401 is about 861.9804731232.

It can be divided in two parts, 640 and 460401, that added together give a square (461041 = 679²).

The spelling of 640460401 in words is "six hundred forty million, four hundred sixty thousand, four hundred one".