20720634 has 16 divisors (see below), whose sum is σ = 45208800. Its totient is φ = 6278960.

The previous prime is 20720633. The next prime is 20720653. The reversal of 20720634 is 43602702.

It is not an unprimeable number, because it can be changed into a prime (20720633) 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, 156909 + ... + 157040.

It is an arithmetic number, because the mean of its divisors is an integer number (2825550).

Almost surely, 2^20720634 is an apocalyptic number.

20720634 is an abundant number, since it is smaller than the sum of its proper divisors (24488166).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20720634 is a wasteful number, since it uses less digits than its factorization.

20720634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313965.

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 20720634 is about 4551.9923110656. The cubic root of 20720634 is about 274.6635400274.

The spelling of 20720634 in words is "twenty million, seven hundred twenty thousand, six hundred thirty-four".