78551131 has 2 divisors, whose sum is σ = 78551132. Its totient is φ = 78551130.

The previous prime is 78551113. The next prime is 78551183. The reversal of 78551131 is 13115587.

Together with previous prime (78551113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78551131 - 2¹⁷ = 78420059 is a prime.

It is a super-2 number, since 2×78551131² = 12340560362758322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78551093 and 78551102.

It is not a weakly prime, because it can be changed into another prime (78558131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39275565 + 39275566.

It is an arithmetic number, because the mean of its divisors is an integer number (39275566).

Almost surely, 2^78551131 is an apocalyptic number.

78551131 is a deficient number, since it is larger than the sum of its proper divisors (1).

78551131 is an equidigital number, since it uses as much as digits as its factorization.

78551131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 31.

The square root of 78551131 is about 8862.9075928840. The cubic root of 78551131 is about 428.2698297791.

The spelling of 78551131 in words is "seventy-eight million, five hundred fifty-one thousand, one hundred thirty-one".