20720464 has 20 divisors (see below), whose sum is σ = 40517620. Its totient is φ = 10265184.

The previous prime is 20720459. The next prime is 20720519. The reversal of 20720464 is 46402702.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 8526400 + 12194064 = 2920^2 + 3492^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190042 + ... + 190150.

It is an arithmetic number, because the mean of its divisors is an integer number (2025881).

Almost surely, 2^20720464 is an apocalyptic number.

It is an amenable number.

20720464 is a deficient number, since it is larger than the sum of its proper divisors (19797156).

20720464 is an frugal number, since it uses more digits than its factorization.

20720464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 20720464 is about 4551.9736378850. The cubic root of 20720464 is about 274.6627888771.

The spelling of 20720464 in words is "twenty million, seven hundred twenty thousand, four hundred sixty-four".