1580020661 has 2 divisors, whose sum is σ = 1580020662. Its totient is φ = 1580020660.

The previous prime is 1580020633. The next prime is 1580020691. The reversal of 1580020661 is 1660200851.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1248562225 + 331458436 = 35335^2 + 18206^2 .

It is a cyclic number.

It is not a de Polignac number, because 1580020661 - 2³⁰ = 506278837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1580020691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 790010330 + 790010331.

It is an arithmetic number, because the mean of its divisors is an integer number (790010331).

Almost surely, 2^1580020661 is an apocalyptic number.

It is an amenable number.

1580020661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1580020661 is an equidigital number, since it uses as much as digits as its factorization.

1580020661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 1580020661 is about 39749.4737197865. The cubic root of 1580020661 is about 1164.7183613127.

The spelling of 1580020661 in words is "one billion, five hundred eighty million, twenty thousand, six hundred sixty-one".