20131000 has 64 divisors (see below), whose sum is σ = 48353760. Its totient is φ = 7840000.

The previous prime is 20130983. The next prime is 20131019. The reversal of 20131000 is 13102.

It is a super-2 number, since 2×20131000² = 810514322000000, which contains 22 as substring.

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, 40755 + ... + 41245.

Almost surely, 2^20131000 is an apocalyptic number.

20131000 is a gapful number since it is divisible by the number (20) 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 20131000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24176880).

20131000 is an abundant number, since it is smaller than the sum of its proper divisors (28222760).

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

20131000 is a wasteful number, since it uses less digits than its factorization.

20131000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 7.

The square root of 20131000 is about 4486.7582952506. The cubic root of 20131000 is about 272.0331202461.

Adding to 20131000 its reverse (13102), we get a palindrome (20144102).

The spelling of 20131000 in words is "twenty million, one hundred thirty-one thousand".