20894640 has 160 divisors (see below), whose sum is σ = 72037056. Its totient is φ = 4976640.

The previous prime is 20894633. The next prime is 20894641. The reversal of 20894640 is 4649802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20894641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115350 + ... + 115530.

Almost surely, 2^20894640 is an apocalyptic number.

20894640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20894640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36018528).

20894640 is an abundant number, since it is smaller than the sum of its proper divisors (51142416).

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

20894640 is a wasteful number, since it uses less digits than its factorization.

20894640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247 (or 241 counting only the distinct ones).

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

The square root of 20894640 is about 4571.0655212981. The cubic root of 20894640 is about 275.4302466240.

The spelling of 20894640 in words is "twenty million, eight hundred ninety-four thousand, six hundred forty".