640251463 has 8 divisors (see below), whose sum is σ = 662533760. Its totient is φ = 618071040.

The previous prime is 640251461. The next prime is 640251487. The reversal of 640251463 is 364152046.

640251463 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 640251463 - 2¹ = 640251461 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640251461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12570 + ... + 37927.

It is an arithmetic number, because the mean of its divisors is an integer number (82816720).

Almost surely, 2^640251463 is an apocalyptic number.

640251463 is a deficient number, since it is larger than the sum of its proper divisors (22282297).

640251463 is a wasteful number, since it uses less digits than its factorization.

640251463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50937.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 640251463 is about 25303.1907671740. The cubic root of 640251463 is about 861.8867280276.

The spelling of 640251463 in words is "six hundred forty million, two hundred fifty-one thousand, four hundred sixty-three".