20256540 has 24 divisors (see below), whose sum is σ = 56718480. Its totient is φ = 5401728.

The previous prime is 20256539. The next prime is 20256541. The reversal of 20256540 is 4565202.

It is an interprime number because it is at equal distance from previous prime (20256539) and next prime (20256541).

It is a self number, because there is not a number n which added to its sum of digits gives 20256540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20256541) 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, 168745 + ... + 168864.

It is an arithmetic number, because the mean of its divisors is an integer number (2363270).

Almost surely, 2^20256540 is an apocalyptic number.

20256540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20256540 is an abundant number, since it is smaller than the sum of its proper divisors (36461940).

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

20256540 is a wasteful number, since it uses less digits than its factorization.

20256540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337621 (or 337619 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20256540 is about 4500.7266080045. The cubic root of 20256540 is about 272.5974288990.

The spelling of 20256540 in words is "twenty million, two hundred fifty-six thousand, five hundred forty".