640621553254 has 16 divisors (see below), whose sum is σ = 979632299520. Its totient is φ = 314084480320.

The previous prime is 640621553249. The next prime is 640621553287. The reversal of 640621553254 is 452355126046.

It is a self number, because there is not a number n which added to its sum of digits gives 640621553254.

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, 1573414 + ... + 1938265.

It is an arithmetic number, because the mean of its divisors is an integer number (61227018720).

Almost surely, 2^640621553254 is an apocalyptic number.

640621553254 is a deficient number, since it is larger than the sum of its proper divisors (339010746266).

640621553254 is a wasteful number, since it uses less digits than its factorization.

640621553254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3513455.

The product of its (nonzero) digits is 864000, while the sum is 43.

The spelling of 640621553254 in words is "six hundred forty billion, six hundred twenty-one million, five hundred fifty-three thousand, two hundred fifty-four".