78537120781 has 8 divisors (see below), whose sum is σ = 90595558080. Its totient is φ = 66688395648.

The previous prime is 78537120709. The next prime is 78537120799. The reversal of 78537120781 is 18702173587.

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

It is not a de Polignac number, because 78537120781 - 2¹⁵ = 78537088013 is a prime.

It is a super-2 number, since 2×78537120781² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78537120281) 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, 52427236 + ... + 52428733.

It is an arithmetic number, because the mean of its divisors is an integer number (11324444760).

Almost surely, 2^78537120781 is an apocalyptic number.

It is an amenable number.

78537120781 is a deficient number, since it is larger than the sum of its proper divisors (12058437299).

78537120781 is a wasteful number, since it uses less digits than its factorization.

78537120781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104856083.

The product of its (nonzero) digits is 658560, while the sum is 49.

The spelling of 78537120781 in words is "seventy-eight billion, five hundred thirty-seven million, one hundred twenty thousand, seven hundred eighty-one".