78156998 has 4 divisors (see below), whose sum is σ = 117235500. Its totient is φ = 39078498.

The previous prime is 78156997. The next prime is 78157031. The reversal of 78156998 is 89965187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89965187 = 13 ⋅6920399.

It is a super-2 number, since 2×78156998² = 12217032672744008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78156997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19539248 + ... + 19539251.

It is an arithmetic number, because the mean of its divisors is an integer number (29308875).

Almost surely, 2^78156998 is an apocalyptic number.

78156998 is a deficient number, since it is larger than the sum of its proper divisors (39078502).

78156998 is a wasteful number, since it uses less digits than its factorization.

78156998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39078501.

The product of its digits is 1088640, while the sum is 53.

The square root of 78156998 is about 8840.6446597519. The cubic root of 78156998 is about 427.5523422339.

The spelling of 78156998 in words is "seventy-eight million, one hundred fifty-six thousand, nine hundred ninety-eight".