129679221 has 16 divisors (see below), whose sum is σ = 206198784. Its totient is φ = 70880304.

The previous prime is 129679219. The next prime is 129679223. The reversal of 129679221 is 122976921.

It is an interprime number because it is at equal distance from previous prime (129679219) and next prime (129679223).

It is not a de Polignac number, because 129679221 - 2¹ = 129679219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129679221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129679223) 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, 133761 + ... + 134726.

It is an arithmetic number, because the mean of its divisors is an integer number (12887424).

Almost surely, 2^129679221 is an apocalyptic number.

It is an amenable number.

129679221 is a deficient number, since it is larger than the sum of its proper divisors (76519563).

129679221 is a wasteful number, since it uses less digits than its factorization.

129679221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268520.

The product of its digits is 27216, while the sum is 39.

The square root of 129679221 is about 11387.6784728056. The cubic root of 129679221 is about 506.1626917261.

The spelling of 129679221 in words is "one hundred twenty-nine million, six hundred seventy-nine thousand, two hundred twenty-one".