1638780462879 has 16 divisors (see below), whose sum is σ = 2605762724352. Its totient is φ = 895730935968.

The previous prime is 1638780462817. The next prime is 1638780462887. The reversal of 1638780462879 is 9782640878361.

It is not a de Polignac number, because 1638780462879 - 2¹⁶ = 1638780397343 is a prime.

It is a super-3 number, since 3×1638780462879³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638780462899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1696459624 + ... + 1696460589.

It is an arithmetic number, because the mean of its divisors is an integer number (162860170272).

Almost surely, 2^{1638780462879} is an apocalyptic number.

1638780462879 is a deficient number, since it is larger than the sum of its proper divisors (966982261473).

1638780462879 is a wasteful number, since it uses less digits than its factorization.

1638780462879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3392920246.

The product of its (nonzero) digits is 195084288, while the sum is 69.

The spelling of 1638780462879 in words is "one trillion, six hundred thirty-eight billion, seven hundred eighty million, four hundred sixty-two thousand, eight hundred seventy-nine".