20871730 has 16 divisors (see below), whose sum is σ = 40984704. Its totient is φ = 7589680.

The previous prime is 20871707. The next prime is 20871731. The reversal of 20871730 is 3717802.

It is a happy number.

It is a super-2 number, since 2×20871730² = 871258226385800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20871731) 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, 94762 + ... + 94981.

It is an arithmetic number, because the mean of its divisors is an integer number (2561544).

Almost surely, 2^20871730 is an apocalyptic number.

20871730 is a deficient number, since it is larger than the sum of its proper divisors (20112974).

20871730 is a wasteful number, since it uses less digits than its factorization.

20871730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189761.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 20871730 is about 4568.5588537306. The cubic root of 20871730 is about 275.3295443290.

The spelling of 20871730 in words is "twenty million, eight hundred seventy-one thousand, seven hundred thirty".