640551332 has 12 divisors (see below), whose sum is σ = 1179963120. Its totient is φ = 303419016.

The previous prime is 640551299. The next prime is 640551341. The reversal of 640551332 is 233155046.

It is a junction number, because it is equal to n+sod(n) for n = 640551295 and 640551304.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4214078 + ... + 4214229.

It is an arithmetic number, because the mean of its divisors is an integer number (98330260).

Almost surely, 2^640551332 is an apocalyptic number.

It is an amenable number.

640551332 is a deficient number, since it is larger than the sum of its proper divisors (539411788).

640551332 is a wasteful number, since it uses less digits than its factorization.

640551332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8428330 (or 8428328 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 29.

The square root of 640551332 is about 25309.1155910277. The cubic root of 640551332 is about 862.0212651519.

The spelling of 640551332 in words is "six hundred forty million, five hundred fifty-one thousand, three hundred thirty-two".