78681021 has 8 divisors (see below), whose sum is σ = 105576864. Its totient is φ = 52119600.

The previous prime is 78680989. The next prime is 78681037. The reversal of 78681021 is 12018687.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78681021 - 2⁵ = 78680989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78681041) 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, 83055 + ... + 83996.

It is an arithmetic number, because the mean of its divisors is an integer number (13197108).

Almost surely, 2^78681021 is an apocalyptic number.

It is an amenable number.

78681021 is a deficient number, since it is larger than the sum of its proper divisors (26895843).

78681021 is a wasteful number, since it uses less digits than its factorization.

78681021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167211.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 78681021 is about 8870.2322968454. The cubic root of 78681021 is about 428.5057582076.

The spelling of 78681021 in words is "seventy-eight million, six hundred eighty-one thousand, twenty-one".