20521621425 has 12 divisors (see below), whose sum is σ = 33929080880. Its totient is φ = 10944864720.

The previous prime is 20521621381. The next prime is 20521621489. The reversal of 20521621425 is 52412612502.

It is not a de Polignac number, because 20521621425 - 2¹⁸ = 20521359281 is a prime.

It is a super-2 number, since 2×20521621425² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20521621392 and 20521621401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136810735 + ... + 136810884.

Almost surely, 2^20521621425 is an apocalyptic number.

20521621425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20521621425 is a deficient number, since it is larger than the sum of its proper divisors (13407459455).

20521621425 is a wasteful number, since it uses less digits than its factorization.

20521621425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273621632 (or 273621627 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The spelling of 20521621425 in words is "twenty billion, five hundred twenty-one million, six hundred twenty-one thousand, four hundred twenty-five".