78021361 has 4 divisors (see below), whose sum is σ = 85114224. Its totient is φ = 70928500.

The previous prime is 78021343. The next prime is 78021371. The reversal of 78021361 is 16312087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78021361 - 2⁵ = 78021329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78021371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3546415 + ... + 3546436.

It is an arithmetic number, because the mean of its divisors is an integer number (21278556).

Almost surely, 2^78021361 is an apocalyptic number.

It is an amenable number.

78021361 is a deficient number, since it is larger than the sum of its proper divisors (7092863).

78021361 is a wasteful number, since it uses less digits than its factorization.

78021361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7092862.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 78021361 is about 8832.9701120291. The cubic root of 78021361 is about 427.3048681407.

The spelling of 78021361 in words is "seventy-eight million, twenty-one thousand, three hundred sixty-one".