20549640 has 64 divisors (see below), whose sum is σ = 64900800. Its totient is φ = 5190912.

The previous prime is 20549611. The next prime is 20549647. The reversal of 20549640 is 4694502.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20549598 and 20549607.

It is not an unprimeable number, because it can be changed into a prime (20549647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2227 + ... + 6786.

It is an arithmetic number, because the mean of its divisors is an integer number (1014075).

Almost surely, 2^20549640 is an apocalyptic number.

20549640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20549640 is an abundant number, since it is smaller than the sum of its proper divisors (44351160).

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

20549640 is a wasteful number, since it uses less digits than its factorization.

20549640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9046 (or 9042 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 20549640 is about 4533.1710755276. The cubic root of 20549640 is about 273.9059118938.

The spelling of 20549640 in words is "twenty million, five hundred forty-nine thousand, six hundred forty".