78088621 has 4 divisors (see below), whose sum is σ = 84095452. Its totient is φ = 72081792.

The previous prime is 78088553. The next prime is 78088627. The reversal of 78088621 is 12688087.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51194025 + 26894596 = 7155^2 + 5186^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78088621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78088627) 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, 3003396 + ... + 3003421.

It is an arithmetic number, because the mean of its divisors is an integer number (21023863).

Almost surely, 2^78088621 is an apocalyptic number.

It is an amenable number.

78088621 is a deficient number, since it is larger than the sum of its proper divisors (6006831).

78088621 is a wasteful number, since it uses less digits than its factorization.

78088621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6006830.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 78088621 is about 8836.7766182019. The cubic root of 78088621 is about 427.4276220046.

It can be divided in two parts, 780 and 88621, that added together give a square (89401 = 299²).

The spelling of 78088621 in words is "seventy-eight million, eighty-eight thousand, six hundred twenty-one".