78405321 has 8 divisors (see below), whose sum is σ = 109085760. Its totient is φ = 49997552.

The previous prime is 78405319. The next prime is 78405323. The reversal of 78405321 is 12350487.

It is an interprime number because it is at equal distance from previous prime (78405319) and next prime (78405323).

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 78405321 - 2¹ = 78405319 is a prime.

It is a super-2 number, since 2×78405321² = 12294788722226082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78405323) 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, 568086 + ... + 568223.

It is an arithmetic number, because the mean of its divisors is an integer number (13635720).

Almost surely, 2^78405321 is an apocalyptic number.

It is an amenable number.

78405321 is a deficient number, since it is larger than the sum of its proper divisors (30680439).

78405321 is a wasteful number, since it uses less digits than its factorization.

78405321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136335.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 78405321 is about 8854.6779162203. The cubic root of 78405321 is about 428.0046746658.

The spelling of 78405321 in words is "seventy-eight million, four hundred five thousand, three hundred twenty-one".