20251840 has 56 divisors (see below), whose sum is σ = 55120032. Its totient is φ = 6942720.

The previous prime is 20251837. The next prime is 20251841. The reversal of 20251840 is 4815202.

It is a tau number, because it is divible by the number of its divisors (56).

It is not an unprimeable number, because it can be changed into a prime (20251841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2281 + ... + 6760.

Almost surely, 2^20251840 is an apocalyptic number.

20251840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20251840 is an abundant number, since it is smaller than the sum of its proper divisors (34868192).

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

20251840 is an equidigital number, since it uses as much as digits as its factorization.

20251840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9065 (or 9055 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 20251840 is about 4500.2044398005. The cubic root of 20251840 is about 272.5763442350.

The spelling of 20251840 in words is "twenty million, two hundred fifty-one thousand, eight hundred forty".