20309629 has 4 divisors (see below), whose sum is σ = 20653920. Its totient is φ = 19965340.

The previous prime is 20309591. The next prime is 20309683. The reversal of 20309629 is 92690302.

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 a cyclic number.

It is not a de Polignac number, because 20309629 - 2⁷ = 20309501 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 20309629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172057 + ... + 172174.

It is an arithmetic number, because the mean of its divisors is an integer number (5163480).

Almost surely, 2^20309629 is an apocalyptic number.

It is an amenable number.

20309629 is a deficient number, since it is larger than the sum of its proper divisors (344291).

20309629 is an equidigital number, since it uses as much as digits as its factorization.

20309629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344290.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 20309629 is about 4506.6205742219. The cubic root of 20309629 is about 272.8353652305.

The spelling of 20309629 in words is "twenty million, three hundred nine thousand, six hundred twenty-nine".