1655563561 has 2 divisors, whose sum is σ = 1655563562. Its totient is φ = 1655563560.

The previous prime is 1655563549. The next prime is 1655563573. The reversal of 1655563561 is 1653655561.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1655563549) and next prime (1655563573).

It can be written as a sum of positive squares in only one way, i.e., 1130237161 + 525326400 = 33619^2 + 22920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1655563561 - 2⁷ = 1655563433 is a prime.

It is a super-2 number, since 2×1655563561² = 5481781409022001442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1655563061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 827781780 + 827781781.

It is an arithmetic number, because the mean of its divisors is an integer number (827781781).

Almost surely, 2^1655563561 is an apocalyptic number.

It is an amenable number.

1655563561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1655563561 is an equidigital number, since it uses as much as digits as its factorization.

1655563561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 405000, while the sum is 43.

The square root of 1655563561 is about 40688.6170937278. The cubic root of 1655563561 is about 1182.9923957470.

The spelling of 1655563561 in words is "one billion, six hundred fifty-five million, five hundred sixty-three thousand, five hundred sixty-one".