20581740 has 36 divisors (see below), whose sum is σ = 62431824. Its totient is φ = 5488416.

The previous prime is 20581721. The next prime is 20581777. The reversal of 20581740 is 4718502.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56992 + ... + 57351.

Almost surely, 2^20581740 is an apocalyptic number.

20581740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20581740 is an abundant number, since it is smaller than the sum of its proper divisors (41850084).

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

20581740 is a wasteful number, since it uses less digits than its factorization.

20581740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114358 (or 114353 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20581740 is about 4536.7102618527. The cubic root of 20581740 is about 274.0484578724.

It can be divided in two parts, 20581 and 740, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20581740 in words is "twenty million, five hundred eighty-one thousand, seven hundred forty".