20525111989 has 2 divisors, whose sum is σ = 20525111990. Its totient is φ = 20525111988.

The previous prime is 20525111983. The next prime is 20525112001. The reversal of 20525111989 is 98911152502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17226562500 + 3298549489 = 131250^2 + 57433^2 .

It is a cyclic number.

It is not a de Polignac number, because 20525111989 - 2¹⁵ = 20525079221 is a prime.

It is a super-2 number, since 2×20525111989² (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 (20525111983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10262555994 + 10262555995.

It is an arithmetic number, because the mean of its divisors is an integer number (10262555995).

Almost surely, 2^20525111989 is an apocalyptic number.

It is an amenable number.

20525111989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20525111989 is an equidigital number, since it uses as much as digits as its factorization.

20525111989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 43.

The spelling of 20525111989 in words is "twenty billion, five hundred twenty-five million, one hundred eleven thousand, nine hundred eighty-nine".