87724231639 has 4 divisors (see below), whose sum is σ = 95699161800. Its totient is φ = 79749301480.

The previous prime is 87724231633. The next prime is 87724231663. The reversal of 87724231639 is 93613242778.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87724231639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87724231633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3987465064 + ... + 3987465085.

It is an arithmetic number, because the mean of its divisors is an integer number (23924790450).

Almost surely, 2^87724231639 is an apocalyptic number.

87724231639 is a deficient number, since it is larger than the sum of its proper divisors (7974930161).

87724231639 is a wasteful number, since it uses less digits than its factorization.

87724231639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7974930160.

The product of its digits is 3048192, while the sum is 52.

The spelling of 87724231639 in words is "eighty-seven billion, seven hundred twenty-four million, two hundred thirty-one thousand, six hundred thirty-nine".