78155413 has 4 divisors (see below), whose sum is σ = 89320480. Its totient is φ = 66990348.

The previous prime is 78155393. The next prime is 78155437. The reversal of 78155413 is 31455187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31455187 = 197 ⋅159671.

It is a cyclic number.

It is not a de Polignac number, because 78155413 - 2¹⁷ = 78024341 is a prime.

It is a super-2 number, since 2×78155413² = 12216537162401138, which 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 (78159413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5582523 + ... + 5582536.

It is an arithmetic number, because the mean of its divisors is an integer number (22330120).

Almost surely, 2^78155413 is an apocalyptic number.

It is an amenable number.

78155413 is a deficient number, since it is larger than the sum of its proper divisors (11165067).

78155413 is a wasteful number, since it uses less digits than its factorization.

78155413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11165066.

The product of its digits is 16800, while the sum is 34.

The square root of 78155413 is about 8840.5550165134. Note that the first 3 decimals coincide. The cubic root of 78155413 is about 427.5494520042.

The spelling of 78155413 in words is "seventy-eight million, one hundred fifty-five thousand, four hundred thirteen".