20557830 has 32 divisors (see below), whose sum is σ = 49724928. Its totient is φ = 5439200.

The previous prime is 20557819. The next prime is 20557853. The reversal of 20557830 is 3875502.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1315 + ... + 6545.

It is an arithmetic number, because the mean of its divisors is an integer number (1553904).

Almost surely, 2^20557830 is an apocalyptic number.

20557830 is an abundant number, since it is smaller than the sum of its proper divisors (29167098).

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

20557830 is a wasteful number, since it uses less digits than its factorization.

20557830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5372.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 20557830 is about 4534.0743266956. The cubic root of 20557830 is about 273.9422951989.

The spelling of 20557830 in words is "twenty million, five hundred fifty-seven thousand, eight hundred thirty".