1604722261 has 2 divisors, whose sum is σ = 1604722262. Its totient is φ = 1604722260.

The previous prime is 1604722253. The next prime is 1604722267. The reversal of 1604722261 is 1622274061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1101841636 + 502880625 = 33194^2 + 22425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1604722261 - 2³ = 1604722253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1604722267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802361130 + 802361131.

It is an arithmetic number, because the mean of its divisors is an integer number (802361131).

Almost surely, 2^1604722261 is an apocalyptic number.

It is an amenable number.

1604722261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1604722261 is an equidigital number, since it uses as much as digits as its factorization.

1604722261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 1604722261 is about 40058.9847724577. The cubic root of 1604722261 is about 1170.7566296862.

The spelling of 1604722261 in words is "one billion, six hundred four million, seven hundred twenty-two thousand, two hundred sixty-one".