78131532531 has 8 divisors (see below), whose sum is σ = 112188867280. Its totient is φ = 48080943072.

The previous prime is 78131532503. The next prime is 78131532541. The reversal of 78131532531 is 13523513187.

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

It is not a de Polignac number, because 78131532531 - 2⁶ = 78131532467 is a prime.

It is a super-2 number, since 2×78131532531² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 2003372629 = 78131532531 / (7 + 8 + 1 + 3 + 1 + 5 + 3 + 2 + 5 + 3 + 1).

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 78131532531.

It is not an unprimeable number, because it can be changed into a prime (78131532541) 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, 1001686276 + ... + 1001686353.

It is an arithmetic number, because the mean of its divisors is an integer number (14023608410).

Almost surely, 2^78131532531 is an apocalyptic number.

78131532531 is a deficient number, since it is larger than the sum of its proper divisors (34057334749).

78131532531 is a wasteful number, since it uses less digits than its factorization.

78131532531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2003372645.

The product of its digits is 75600, while the sum is 39.

The spelling of 78131532531 in words is "seventy-eight billion, one hundred thirty-one million, five hundred thirty-two thousand, five hundred thirty-one".