20025661 has 2 divisors, whose sum is σ = 20025662. Its totient is φ = 20025660.

The previous prime is 20025637. The next prime is 20025667. The reversal of 20025661 is 16652002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20025625 + 36 = 4475^2 + 6^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20025661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20025667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10012830 + 10012831.

It is an arithmetic number, because the mean of its divisors is an integer number (10012831).

Almost surely, 2^20025661 is an apocalyptic number.

It is an amenable number.

20025661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20025661 is an equidigital number, since it uses as much as digits as its factorization.

20025661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20025661 is about 4475.0040223446. The cubic root of 20025661 is about 271.5578031620.

Adding to 20025661 its reverse (16652002), we get a palindrome (36677663).

The spelling of 20025661 in words is "twenty million, twenty-five thousand, six hundred sixty-one".