28987998631 has 8 divisors (see below), whose sum is σ = 29019165728. Its totient is φ = 28956852000.

The previous prime is 28987998623. The next prime is 28987998643. The reversal of 28987998631 is 13689978982.

28987998631 = T₁ + T₂ + ... + T₅₅₈₁.

28987998631 is a nontrivial binomial coefficient, being equal to C(5583, 3).

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

It is a 5-Lehmer number, since φ(28987998631) divides (28987998631-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 28987998631 - 2³ = 28987998623 is a prime.

It is a super-4 number, since 4×28987998631⁴ (a number of 43 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28987998671) by changing a digit.

It is the 5581-st tetrahedral number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5191261 + ... + 5196841.

It is an arithmetic number, because the mean of its divisors is an integer number (3627395716).

Almost surely, 2^28987998631 is an apocalyptic number.

28987998631 is a deficient number, since it is larger than the sum of its proper divisors (31167097).

28987998631 is a wasteful number, since it uses less digits than its factorization.

28987998631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10233.

The product of its digits is 94058496, while the sum is 70.

The spelling of 28987998631 in words is "twenty-eight billion, nine hundred eighty-seven million, nine hundred ninety-eight thousand, six hundred thirty-one".