20505261425 has 24 divisors (see below), whose sum is σ = 28261405440. Its totient is φ = 14631531200.

The previous prime is 20505261421. The next prime is 20505261437. The reversal of 20505261425 is 52416250502.

It is not a de Polignac number, because 20505261425 - 2² = 20505261421 is a prime.

It is a super-2 number, since 2×20505261425² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20505261391 and 20505261400.

It is not an unprimeable number, because it can be changed into a prime (20505261421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 688865 + ... + 718014.

It is an arithmetic number, because the mean of its divisors is an integer number (1177558560).

Almost surely, 2^20505261425 is an apocalyptic number.

20505261425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20505261425 is a deficient number, since it is larger than the sum of its proper divisors (7756144015).

20505261425 is a wasteful number, since it uses less digits than its factorization.

20505261425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406953 (or 1406948 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 32.

The spelling of 20505261425 in words is "twenty billion, five hundred five million, two hundred sixty-one thousand, four hundred twenty-five".