78421761 has 24 divisors (see below), whose sum is σ = 124057440. Its totient is φ = 47342400.

The previous prime is 78421757. The next prime is 78421769. The reversal of 78421761 is 16712487.

It is not a de Polignac number, because 78421761 - 2² = 78421757 is a prime.

It is a super-2 number, since 2×78421761² = 12299945196682242, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (78421769) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26410 + ... + 29228.

It is an arithmetic number, because the mean of its divisors is an integer number (5169060).

Almost surely, 2^78421761 is an apocalyptic number.

It is an amenable number.

78421761 is a deficient number, since it is larger than the sum of its proper divisors (45635679).

78421761 is a wasteful number, since it uses less digits than its factorization.

78421761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3117 (or 3114 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 78421761 is about 8855.6061904310. The cubic root of 78421761 is about 428.0345871982.

The spelling of 78421761 in words is "seventy-eight million, four hundred twenty-one thousand, seven hundred sixty-one".