78233721 has 8 divisors (see below), whose sum is σ = 104352864. Its totient is φ = 52135200.

The previous prime is 78233717. The next prime is 78233723. The reversal of 78233721 is 12733287.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78233721 - 2² = 78233717 is a prime.

It is a super-2 number, since 2×78233721² = 12241030203011682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78233723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10446 + ... + 16296.

It is an arithmetic number, because the mean of its divisors is an integer number (13044108).

Almost surely, 2^78233721 is an apocalyptic number.

It is an amenable number.

78233721 is a deficient number, since it is larger than the sum of its proper divisors (26119143).

78233721 is a wasteful number, since it uses less digits than its factorization.

78233721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10311.

The product of its digits is 14112, while the sum is 33.

The square root of 78233721 is about 8844.9828151331. The cubic root of 78233721 is about 427.6921990661.

The spelling of 78233721 in words is "seventy-eight million, two hundred thirty-three thousand, seven hundred twenty-one".