20515554225 has 36 divisors (see below), whose sum is σ = 36774278736. Its totient is φ = 10933100640.

The previous prime is 20515554203. The next prime is 20515554229. The reversal of 20515554225 is 52245551502.

It is not a de Polignac number, because 20515554225 - 2⁹ = 20515553713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20515554225.

It is not an unprimeable number, because it can be changed into a prime (20515554229) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 259194 + ... + 328956.

Almost surely, 2^20515554225 is an apocalyptic number.

20515554225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20515554225 is a deficient number, since it is larger than the sum of its proper divisors (16258724511).

20515554225 is a wasteful number, since it uses less digits than its factorization.

20515554225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71086 (or 71078 counting only the distinct ones).

The product of its (nonzero) digits is 100000, while the sum is 36.

The spelling of 20515554225 in words is "twenty billion, five hundred fifteen million, five hundred fifty-four thousand, two hundred twenty-five".