20909297525 has 6 divisors (see below), whose sum is σ = 25927528962. Its totient is φ = 16727438000.

The previous prime is 20909297459. The next prime is 20909297531. The reversal of 20909297525 is 52579290902.

It can be written as a sum of positive squares in 3 ways, for example, as 2576679121 + 18332618404 = 50761^2 + 135398^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20909297525 is a prime.

It is a super-2 number, since 2×20909297525² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 418185926 + ... + 418185975.

It is an arithmetic number, because the mean of its divisors is an integer number (4321254827).

Almost surely, 2^20909297525 is an apocalyptic number.

20909297525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20909297525 is a deficient number, since it is larger than the sum of its proper divisors (5018231437).

20909297525 is an equidigital number, since it uses as much as digits as its factorization.

20909297525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836371911 (or 836371906 counting only the distinct ones).

The product of its (nonzero) digits is 1020600, while the sum is 50.

The spelling of 20909297525 in words is "twenty billion, nine hundred nine million, two hundred ninety-seven thousand, five hundred twenty-five".