21803932520 has 32 divisors (see below), whose sum is σ = 49544588520. Its totient is φ = 8635219200.

The previous prime is 21803932499. The next prime is 21803932529. The reversal of 21803932520 is 2523930812.

It can be written as a sum of positive squares in 4 ways, for example, as 21020940196 + 782992324 = 144986^2 + 27982^2 .

It is a super-2 number, since 2×21803932520² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21803932529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2694467 + ... + 2702546.

Almost surely, 2^21803932520 is an apocalyptic number.

21803932520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21803932520 is an abundant number, since it is smaller than the sum of its proper divisors (27740656000).

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

21803932520 is a wasteful number, since it uses less digits than its factorization.

21803932520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5397125 (or 5397121 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 21803932520 in words is "twenty-one billion, eight hundred three million, nine hundred thirty-two thousand, five hundred twenty".