20631420 has 72 divisors (see below), whose sum is σ = 63641760. Its totient is φ = 5408640.

The previous prime is 20631409. The next prime is 20631433. The reversal of 20631420 is 2413602.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20631393 and 20631402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10041 + ... + 11919.

Almost surely, 2^20631420 is an apocalyptic number.

20631420 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 20631420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31820880).

20631420 is an abundant number, since it is smaller than the sum of its proper divisors (43010340).

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

20631420 is a wasteful number, since it uses less digits than its factorization.

20631420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1955 (or 1950 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 20631420 is about 4542.1822948887. The cubic root of 20631420 is about 274.2687791813.

It can be divided in two parts, 206 and 31420, that added together give a triangular number (31626 = T₂₅₁).

The spelling of 20631420 in words is "twenty million, six hundred thirty-one thousand, four hundred twenty".