20581660 has 24 divisors (see below), whose sum is σ = 47151216. Its totient is φ = 7484160.

The previous prime is 20581651. The next prime is 20581661. The reversal of 20581660 is 6618502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20581661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46557 + ... + 46996.

It is an arithmetic number, because the mean of its divisors is an integer number (1964634).

Almost surely, 2^20581660 is an apocalyptic number.

20581660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20581660 is an abundant number, since it is smaller than the sum of its proper divisors (26569556).

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

20581660 is a wasteful number, since it uses less digits than its factorization.

20581660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93573 (or 93571 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 20581660 is about 4536.7014448826. The cubic root of 20581660 is about 274.0481028020.

The spelling of 20581660 in words is "twenty million, five hundred eighty-one thousand, six hundred sixty".