1445551561 has 2 divisors, whose sum is σ = 1445551562. Its totient is φ = 1445551560.

The previous prime is 1445551537. The next prime is 1445551571. The reversal of 1445551561 is 1651555441.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1427403961 + 18147600 = 37781^2 + 4260^2 .

It is an emirp because it is prime and its reverse (1651555441) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1445551561 - 2⁵ = 1445551529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1445551561.

It is not a weakly prime, because it can be changed into another prime (1445551571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 722775780 + 722775781.

It is an arithmetic number, because the mean of its divisors is an integer number (722775781).

Almost surely, 2^1445551561 is an apocalyptic number.

It is an amenable number.

1445551561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1445551561 is an equidigital number, since it uses as much as digits as its factorization.

1445551561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60000, while the sum is 37.

The square root of 1445551561 is about 38020.4097952665. The cubic root of 1445551561 is about 1130.6925456856.

The spelling of 1445551561 in words is "one billion, four hundred forty-five million, five hundred fifty-one thousand, five hundred sixty-one".