78273921 has 8 divisors (see below), whose sum is σ = 113853024. Its totient is φ = 47438720.

The previous prime is 78273917. The next prime is 78273931. The reversal of 78273921 is 12937287.

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

It is a cyclic number.

It is not a de Polignac number, because 78273921 - 2² = 78273917 is a prime.

It is a super-2 number, since 2×78273921² = 12253613417428482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78273921.

It is not an unprimeable number, because it can be changed into a prime (78273931) 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, 1185936 + ... + 1186001.

It is an arithmetic number, because the mean of its divisors is an integer number (14231628).

Almost surely, 2^78273921 is an apocalyptic number.

It is an amenable number.

78273921 is a deficient number, since it is larger than the sum of its proper divisors (35579103).

78273921 is a wasteful number, since it uses less digits than its factorization.

78273921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371951.

The product of its digits is 42336, while the sum is 39.

The square root of 78273921 is about 8847.2549980206. The cubic root of 78273921 is about 427.7654423434.

The spelling of 78273921 in words is "seventy-eight million, two hundred seventy-three thousand, nine hundred twenty-one".