20025265661 has 2 divisors, whose sum is σ = 20025265662. Its totient is φ = 20025265660.

The previous prime is 20025265621. The next prime is 20025265709. The reversal of 20025265661 is 16656252002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16922107225 + 3103158436 = 130085^2 + 55706^2 .

It is a cyclic number.

It is not a de Polignac number, because 20025265661 - 2¹⁸ = 20025003517 is a prime.

It is a super-2 number, since 2×20025265661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20025265621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10012632830 + 10012632831.

It is an arithmetic number, because the mean of its divisors is an integer number (10012632831).

Almost surely, 2^20025265661 is an apocalyptic number.

It is an amenable number.

20025265661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20025265661 is an equidigital number, since it uses as much as digits as its factorization.

20025265661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 20025265661 in words is "twenty billion, twenty-five million, two hundred sixty-five thousand, six hundred sixty-one".