1012251551561 has 2 divisors, whose sum is σ = 1012251551562. Its totient is φ = 1012251551560.

The previous prime is 1012251551503. The next prime is 1012251551617. The reversal of 1012251551561 is 1651551522101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1009510505536 + 2741046025 = 1004744^2 + 52355^2 .

It is a cyclic number.

It is not a de Polignac number, because 1012251551561 - 2¹⁸ = 1012251289417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1012251551761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 506125775780 + 506125775781.

It is an arithmetic number, because the mean of its divisors is an integer number (506125775781).

Almost surely, 2^{1012251551561} is an apocalyptic number.

It is an amenable number.

1012251551561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1012251551561 is an equidigital number, since it uses as much as digits as its factorization.

1012251551561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15000, while the sum is 35.

The spelling of 1012251551561 in words is "one trillion, twelve billion, two hundred fifty-one million, five hundred fifty-one thousand, five hundred sixty-one".