640409430 has 16 divisors (see below), whose sum is σ = 1536982704. Its totient is φ = 170775840.

The previous prime is 640409389. The next prime is 640409443. The reversal of 640409430 is 34904046.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 21346981 = 640409430 / (6 + 4 + 0 + 4 + 0 + 9 + 4 + 3 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10673461 + ... + 10673520.

It is an arithmetic number, because the mean of its divisors is an integer number (96061419).

Almost surely, 2^640409430 is an apocalyptic number.

640409430 is an abundant number, since it is smaller than the sum of its proper divisors (896573274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640409430 is a wasteful number, since it uses less digits than its factorization.

640409430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21346991.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 640409430 is about 25306.3120584569. The cubic root of 640409430 is about 861.9576056296.

The spelling of 640409430 in words is "six hundred forty million, four hundred nine thousand, four hundred thirty".