20468640 has 48 divisors (see below), whose sum is σ = 64477728. Its totient is φ = 5458176.

The previous prime is 20468627. The next prime is 20468671. The reversal of 20468640 is 4686402.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20468598 and 20468607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20842 + ... + 21801.

It is an arithmetic number, because the mean of its divisors is an integer number (1343286).

Almost surely, 2^20468640 is an apocalyptic number.

20468640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20468640 is an abundant number, since it is smaller than the sum of its proper divisors (44009088).

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

20468640 is a wasteful number, since it uses less digits than its factorization.

20468640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42661 (or 42653 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 20468640 is about 4524.2281109599. The cubic root of 20468640 is about 273.5455553237.

The spelling of 20468640 in words is "twenty million, four hundred sixty-eight thousand, six hundred forty".