78471621 has 12 divisors (see below), whose sum is σ = 113679072. Its totient is φ = 52161576.

The previous prime is 78471619. The next prime is 78471629. The reversal of 78471621 is 12617487.

It is not a de Polignac number, because 78471621 - 2¹ = 78471619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78471629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9441 + ... + 15686.

It is an arithmetic number, because the mean of its divisors is an integer number (9473256).

Almost surely, 2^78471621 is an apocalyptic number.

It is an amenable number.

78471621 is a deficient number, since it is larger than the sum of its proper divisors (35207451).

78471621 is a wasteful number, since it uses less digits than its factorization.

78471621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25480 (or 25477 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 78471621 is about 8858.4209089431. The cubic root of 78471621 is about 428.1252817658.

The spelling of 78471621 in words is "seventy-eight million, four hundred seventy-one thousand, six hundred twenty-one".