20868629 has 4 divisors (see below), whose sum is σ = 21432684. Its totient is φ = 20304576.

The previous prime is 20868623. The next prime is 20868637. The reversal of 20868629 is 92686802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20268004 + 600625 = 4502^2 + 775^2 .

It is a cyclic number.

It is not a de Polignac number, because 20868629 - 2¹² = 20864533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20868623) 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, 281972 + ... + 282045.

It is an arithmetic number, because the mean of its divisors is an integer number (5358171).

Almost surely, 2^20868629 is an apocalyptic number.

It is an amenable number.

20868629 is a deficient number, since it is larger than the sum of its proper divisors (564055).

20868629 is an equidigital number, since it uses as much as digits as its factorization.

20868629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564054.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 20868629 is about 4568.2194561995. The cubic root of 20868629 is about 275.3159080340.

The spelling of 20868629 in words is "twenty million, eight hundred sixty-eight thousand, six hundred twenty-nine".