78607821 has 4 divisors (see below), whose sum is σ = 104810432. Its totient is φ = 52405212.

The previous prime is 78607801. The next prime is 78607843. The reversal of 78607821 is 12870687.

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 not a de Polignac number, because 78607821 - 2¹³ = 78599629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78607821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78607801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13101301 + ... + 13101306.

It is an arithmetic number, because the mean of its divisors is an integer number (26202608).

Almost surely, 2^78607821 is an apocalyptic number.

It is an amenable number.

78607821 is a deficient number, since it is larger than the sum of its proper divisors (26202611).

78607821 is a wasteful number, since it uses less digits than its factorization.

78607821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26202610.

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 78607821 is about 8866.1051764571. The cubic root of 78607821 is about 428.3728318114.

The spelling of 78607821 in words is "seventy-eight million, six hundred seven thousand, eight hundred twenty-one".