1553471561 has 2 divisors, whose sum is σ = 1553471562. Its totient is φ = 1553471560.

The previous prime is 1553471533. The next prime is 1553471599. The reversal of 1553471561 is 1651743551.

It is a happy number.

It is an a-pointer prime, because the next prime (1553471599) can be obtained adding 1553471561 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1456567225 + 96904336 = 38165^2 + 9844^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553471561 - 2¹⁸ = 1553209417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1553471501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776735780 + 776735781.

It is an arithmetic number, because the mean of its divisors is an integer number (776735781).

Almost surely, 2^1553471561 is an apocalyptic number.

It is an amenable number.

1553471561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553471561 is an equidigital number, since it uses as much as digits as its factorization.

1553471561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63000, while the sum is 38.

The square root of 1553471561 is about 39414.1035798101. The cubic root of 1553471561 is about 1158.1578870114.

The spelling of 1553471561 in words is "one billion, five hundred fifty-three million, four hundred seventy-one thousand, five hundred sixty-one".