1251343554521 has 2 divisors, whose sum is σ = 1251343554522. Its totient is φ = 1251343554520.

The previous prime is 1251343554499. The next prime is 1251343554529. The reversal of 1251343554521 is 1254553431521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1039453655296 + 211889899225 = 1019536^2 + 460315^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251343554521 - 2²² = 1251339360217 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251343554529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625671777260 + 625671777261.

It is an arithmetic number, because the mean of its divisors is an integer number (625671777261).

Almost surely, 2^{1251343554521} is an apocalyptic number.

It is an amenable number.

1251343554521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251343554521 is an equidigital number, since it uses as much as digits as its factorization.

1251343554521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360000, while the sum is 41.

The spelling of 1251343554521 in words is "one trillion, two hundred fifty-one billion, three hundred forty-three million, five hundred fifty-four thousand, five hundred twenty-one".