78429381 has 32 divisors (see below), whose sum is σ = 115240320. Its totient is φ = 47241216.

The previous prime is 78429367. The next prime is 78429389. The reversal of 78429381 is 18392487.

78429381 = 154² + 155² + ... + 620².

It is not a de Polignac number, because 78429381 - 2⁹ = 78428869 is a prime.

It is a super-2 number, since 2×78429381² = 12302335608086322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78429389) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 167710 + ... + 168176.

It is an arithmetic number, because the mean of its divisors is an integer number (3601260).

Almost surely, 2^78429381 is an apocalyptic number.

It is an amenable number.

78429381 is a deficient number, since it is larger than the sum of its proper divisors (36810939).

78429381 is a wasteful number, since it uses less digits than its factorization.

78429381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613.

The product of its digits is 96768, while the sum is 42.

The square root of 78429381 is about 8856.0364159143. The cubic root of 78429381 is about 428.0484503482.

The spelling of 78429381 in words is "seventy-eight million, four hundred twenty-nine thousand, three hundred eighty-one".