20712220 has 24 divisors (see below), whose sum is σ = 44049600. Its totient is φ = 8179392.

The previous prime is 20712199. The next prime is 20712221. The reversal of 20712220 is 2221702.

20712220 = T₄₃₁ + T₄₃₂ + ... + T₅₈₈.

It is a junction number, because it is equal to n+sod(n) for n = 20712194 and 20712203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20712221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4975 + ... + 8134.

It is an arithmetic number, because the mean of its divisors is an integer number (1835400).

Almost surely, 2^20712220 is an apocalyptic number.

20712220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20712220 is an abundant number, since it is smaller than the sum of its proper divisors (23337380).

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

20712220 is a wasteful number, since it uses less digits than its factorization.

20712220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13197 (or 13195 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 20712220 is about 4551.0680065233. The cubic root of 20712220 is about 274.6263575758.

Adding to 20712220 its reverse (2221702), we get a palindrome (22933922).

The spelling of 20712220 in words is "twenty million, seven hundred twelve thousand, two hundred twenty".