20506404 has 24 divisors (see below), whose sum is σ = 48169408. Its totient is φ = 6789600.

The previous prime is 20506397. The next prime is 20506417. The reversal of 20506404 is 40460502.

It is a happy number.

It is a super-2 number, since 2×20506404² = 841025210022432, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3847 + ... + 7470.

Almost surely, 2^20506404 is an apocalyptic number.

It is an amenable number.

20506404 is an abundant number, since it is smaller than the sum of its proper divisors (27663004).

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

20506404 is a wasteful number, since it uses less digits than its factorization.

20506404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11475 (or 11473 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20506404 is about 4528.3997173394. The cubic root of 20506404 is about 273.7136796333.

Adding to 20506404 its reverse (40460502), we get a palindrome (60966906).

It can be divided in two parts, 20506 and 404, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20506404 in words is "twenty million, five hundred six thousand, four hundred four".