20155601 has 2 divisors, whose sum is σ = 20155602. Its totient is φ = 20155600.

The previous prime is 20155589. The next prime is 20155607. The reversal of 20155601 is 10655102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14025025 + 6130576 = 3745^2 + 2476^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20155601 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20155607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077800 + 10077801.

It is an arithmetic number, because the mean of its divisors is an integer number (10077801).

Almost surely, 2^20155601 is an apocalyptic number.

It is an amenable number.

20155601 is a deficient number, since it is larger than the sum of its proper divisors (1).

20155601 is an equidigital number, since it uses as much as digits as its factorization.

20155601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 20155601 is about 4489.4989698183. The cubic root of 20155601 is about 272.1438874301.

The spelling of 20155601 in words is "twenty million, one hundred fifty-five thousand, six hundred one".