20551333240 has 16 divisors (see below), whose sum is σ = 46240499880. Its totient is φ = 8220533280.

The previous prime is 20551333219. The next prime is 20551333241. The reversal of 20551333240 is 4233315502.

It is a junction number, because it is equal to n+sod(n) for n = 20551333199 and 20551333208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20551333241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256891626 + ... + 256891705.

Almost surely, 2^20551333240 is an apocalyptic number.

20551333240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20551333240 is an abundant number, since it is smaller than the sum of its proper divisors (25689166640).

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

20551333240 is a wasteful number, since it uses less digits than its factorization.

20551333240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513783342 (or 513783338 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 20551333240 its reverse (4233315502), we get a palindrome (24784648742).

The spelling of 20551333240 in words is "twenty billion, five hundred fifty-one million, three hundred thirty-three thousand, two hundred forty".