20871312 has 80 divisors (see below), whose sum is σ = 67233792. Its totient is φ = 5420160.

The previous prime is 20871311. The next prime is 20871341. The reversal of 20871312 is 21317802.

It is a super-2 number, since 2×20871312² = 871223329202688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (20871311) 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, 873 + ... + 6519.

Almost surely, 2^20871312 is an apocalyptic number.

20871312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20871312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33616896).

20871312 is an abundant number, since it is smaller than the sum of its proper divisors (46362480).

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

20871312 is a wasteful number, since it uses less digits than its factorization.

20871312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5676 (or 5670 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20871312 is about 4568.5131060335. The cubic root of 20871312 is about 275.3277063003.

The spelling of 20871312 in words is "twenty million, eight hundred seventy-one thousand, three hundred twelve".