1331561201 has 2 divisors, whose sum is σ = 1331561202. Its totient is φ = 1331561200.

The previous prime is 1331561171. The next prime is 1331561213. The reversal of 1331561201 is 1021651331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 737176801 + 594384400 = 27151^2 + 24380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331561201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1331561221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665780600 + 665780601.

It is an arithmetic number, because the mean of its divisors is an integer number (665780601).

Almost surely, 2^1331561201 is an apocalyptic number.

It is an amenable number.

1331561201 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331561201 is an equidigital number, since it uses as much as digits as its factorization.

1331561201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1331561201 is about 36490.5631773476. The cubic root of 1331561201 is about 1100.1545791030.

The spelling of 1331561201 in words is "one billion, three hundred thirty-one million, five hundred sixty-one thousand, two hundred one".