20072556 has 72 divisors (see below), whose sum is σ = 60552240. Its totient is φ = 5733504.

The previous prime is 20072543. The next prime is 20072561. The reversal of 20072556 is 65527002.

It is a super-3 number, since 3×20072556³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 3396 + ... + 7188.

Almost surely, 2^20072556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20072556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30276120).

20072556 is an abundant number, since it is smaller than the sum of its proper divisors (40479684).

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

20072556 is a wasteful number, since it uses less digits than its factorization.

20072556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3820 (or 3805 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 20072556 is about 4480.2406185382. The cubic root of 20072556 is about 271.7696109956.

Adding to 20072556 its reverse (65527002), we get a palindrome (85599558).

The spelling of 20072556 in words is "twenty million, seventy-two thousand, five hundred fifty-six".