640616455 has 8 divisors (see below), whose sum is σ = 768891312. Its totient is φ = 512392128.

The previous prime is 640616429. The next prime is 640616461. The reversal of 640616455 is 554616046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640616455 is a prime.

It is a Duffinian number.

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, 26019 + ... + 44251.

It is an arithmetic number, because the mean of its divisors is an integer number (96111414).

Almost surely, 2^640616455 is an apocalyptic number.

640616455 is a deficient number, since it is larger than the sum of its proper divisors (128274857).

640616455 is a wasteful number, since it uses less digits than its factorization.

640616455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25265.

The product of its (nonzero) digits is 86400, while the sum is 37.

The square root of 640616455 is about 25310.4021105948. The cubic root of 640616455 is about 862.0504772310.

The spelling of 640616455 in words is "six hundred forty million, six hundred sixteen thousand, four hundred fifty-five".