43999288621 has 64 divisors (see below), whose sum is σ = 49746493440. Its totient is φ = 38787840000.

The previous prime is 43999288609. The next prime is 43999288649. The reversal of 43999288621 is 12688299934.

It is a cyclic number.

It is not a de Polignac number, because 43999288621 - 2¹⁷ = 43999157549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 43999288621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43999288601) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 197306116 + ... + 197306338.

It is an arithmetic number, because the mean of its divisors is an integer number (777288960).

Almost surely, 2^43999288621 is an apocalyptic number.

43999288621 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

43999288621 is a deficient number, since it is larger than the sum of its proper divisors (5747204819).

43999288621 is a wasteful number, since it uses less digits than its factorization.

43999288621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478.

The product of its digits is 13436928, while the sum is 61.

The spelling of 43999288621 in words is "forty-three billion, nine hundred ninety-nine million, two hundred eighty-eight thousand, six hundred twenty-one".