78366621491 has 8 divisors (see below), whose sum is σ = 78633544704. Its totient is φ = 78100152840.

The previous prime is 78366621481. The next prime is 78366621511. The reversal of 78366621491 is 19412666387.

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

It is a cyclic number.

It is not a de Polignac number, because 78366621491 - 2⁶ = 78366621427 is a prime.

It is a super-2 number, since 2×78366621491² (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 (78366621481) 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, 233546 + ... + 459648.

It is an arithmetic number, because the mean of its divisors is an integer number (9829193088).

Almost surely, 2^78366621491 is an apocalyptic number.

78366621491 is a deficient number, since it is larger than the sum of its proper divisors (266923213).

78366621491 is a wasteful number, since it uses less digits than its factorization.

78366621491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227281.

The product of its digits is 2612736, while the sum is 53.

The spelling of 78366621491 in words is "seventy-eight billion, three hundred sixty-six million, six hundred twenty-one thousand, four hundred ninety-one".