1401605561 has 2 divisors, whose sum is σ = 1401605562. Its totient is φ = 1401605560.

The previous prime is 1401605551. The next prime is 1401605581. The reversal of 1401605561 is 1655061041.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 907877161 + 493728400 = 30131^2 + 22220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1401605561 - 2¹⁸ = 1401343417 is a prime.

It is a super-2 number, since 2×1401605561² = 3928996297252249442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1401605501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 700802780 + 700802781.

It is an arithmetic number, because the mean of its divisors is an integer number (700802781).

Almost surely, 2^1401605561 is an apocalyptic number.

It is an amenable number.

1401605561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1401605561 is an equidigital number, since it uses as much as digits as its factorization.

1401605561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1401605561 is about 37438.0229312393. The cubic root of 1401605561 is about 1119.1164271190.

The spelling of 1401605561 in words is "one billion, four hundred one million, six hundred five thousand, five hundred sixty-one".