20405052 has 36 divisors (see below), whose sum is σ = 52208520. Its totient is φ = 6718752.

The previous prime is 20405041. The next prime is 20405057. The reversal of 20405052 is 25050402.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×20405052² = 832732294245408, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20405057) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 427 + ... + 6402.

Almost surely, 2^20405052 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 20405052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26104260).

20405052 is an abundant number, since it is smaller than the sum of its proper divisors (31803468).

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

20405052 is a wasteful number, since it uses less digits than its factorization.

20405052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6922 (or 6917 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 20405052 is about 4517.1951474339. The cubic root of 20405052 is about 273.2619953958.

Adding to 20405052 its reverse (25050402), we get a palindrome (45455454).

The spelling of 20405052 in words is "twenty million, four hundred five thousand, fifty-two".