78129154 has 4 divisors (see below), whose sum is σ = 117193734. Its totient is φ = 39064576.

The previous prime is 78129133. The next prime is 78129173. The reversal of 78129154 is 45192187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45192187 = 79 ⋅572053.

It can be written as a sum of positive squares in only one way, i.e., 51451929 + 26677225 = 7173^2 + 5165^2 .

It is a super-2 number, since 2×78129154² = 12208329409511432, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19532287 + ... + 19532290.

Almost surely, 2^78129154 is an apocalyptic number.

78129154 is a deficient number, since it is larger than the sum of its proper divisors (39064580).

78129154 is a wasteful number, since it uses less digits than its factorization.

78129154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39064579.

The product of its digits is 20160, while the sum is 37.

The square root of 78129154 is about 8839.0697474338. The cubic root of 78129154 is about 427.5015633243.

The spelling of 78129154 in words is "seventy-eight million, one hundred twenty-nine thousand, one hundred fifty-four".