20860640 has 24 divisors (see below), whose sum is σ = 49283640. Its totient is φ = 8344192.

The previous prime is 20860627. The next prime is 20860643. The reversal of 20860640 is 4606802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20860643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65030 + ... + 65349.

It is an arithmetic number, because the mean of its divisors is an integer number (2053485).

Almost surely, 2^20860640 is an apocalyptic number.

20860640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20860640 is an abundant number, since it is smaller than the sum of its proper divisors (28423000).

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

20860640 is a wasteful number, since it uses less digits than its factorization.

20860640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130394 (or 130386 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20860640 is about 4567.3449617913. The cubic root of 20860640 is about 275.2807710904.

The spelling of 20860640 in words is "twenty million, eight hundred sixty thousand, six hundred forty".