20464890 has 64 divisors (see below), whose sum is σ = 51103872. Its totient is φ = 5241600.

The previous prime is 20464883. The next prime is 20464903. The reversal of 20464890 is 9846402.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 96885 + ... + 97095.

It is an arithmetic number, because the mean of its divisors is an integer number (798498).

Almost surely, 2^20464890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20464890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25551936).

20464890 is an abundant number, since it is smaller than the sum of its proper divisors (30638982).

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

20464890 is a wasteful number, since it uses less digits than its factorization.

20464890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20464890 is about 4523.8136566397. The cubic root of 20464890 is about 273.5288491416.

The spelling of 20464890 in words is "twenty million, four hundred sixty-four thousand, eight hundred ninety".