21000555325 has 12 divisors (see below), whose sum is σ = 26230770900. Its totient is φ = 16677810560.

The previous prime is 21000555319. The next prime is 21000555377. The reversal of 21000555325 is 52355500012.

It can be written as a sum of positive squares in 6 ways, for example, as 2120970916 + 18879584409 = 46054^2 + 137403^2 .

It is not a de Polignac number, because 21000555325 - 2¹³ = 21000547133 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000555293 and 21000555302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3062350 + ... + 3069199.

It is an arithmetic number, because the mean of its divisors is an integer number (2185897575).

Almost surely, 2^21000555325 is an apocalyptic number.

21000555325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21000555325 is a deficient number, since it is larger than the sum of its proper divisors (5230215575).

21000555325 is a wasteful number, since it uses less digits than its factorization.

21000555325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6131696 (or 6131691 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 28.

The spelling of 21000555325 in words is "twenty-one billion, five hundred fifty-five thousand, three hundred twenty-five".