78921629 has 16 divisors (see below), whose sum is σ = 84779520. Its totient is φ = 73327680.

The previous prime is 78921607. The next prime is 78921643. The reversal of 78921629 is 92612987.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 78921629 - 2¹⁶ = 78856093 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 78921629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78921329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94787 + ... + 95615.

It is an arithmetic number, because the mean of its divisors is an integer number (5298720).

Almost surely, 2^78921629 is an apocalyptic number.

It is an amenable number.

78921629 is a deficient number, since it is larger than the sum of its proper divisors (5857891).

78921629 is a wasteful number, since it uses less digits than its factorization.

78921629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980.

The product of its digits is 108864, while the sum is 44.

The square root of 78921629 is about 8883.7846101760. The cubic root of 78921629 is about 428.9421065353.

The spelling of 78921629 in words is "seventy-eight million, nine hundred twenty-one thousand, six hundred twenty-nine".