78290987281 has 16 divisors (see below), whose sum is σ = 90348580224. Its totient is φ = 67198005504.

The previous prime is 78290987279. The next prime is 78290987303. The reversal of 78290987281 is 18278909287.

It is a cyclic number.

It is not a de Polignac number, because 78290987281 - 2¹ = 78290987279 is a prime.

It is a super-2 number, since 2×78290987281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78290987251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2115741 + ... + 2152426.

It is an arithmetic number, because the mean of its divisors is an integer number (5646786264).

Almost surely, 2^78290987281 is an apocalyptic number.

It is an amenable number.

78290987281 is a deficient number, since it is larger than the sum of its proper divisors (12057592943).

78290987281 is a wasteful number, since it uses less digits than its factorization.

78290987281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4268280.

The product of its (nonzero) digits is 8128512, while the sum is 61.

The spelling of 78290987281 in words is "seventy-eight billion, two hundred ninety million, nine hundred eighty-seven thousand, two hundred eighty-one".