1251454400491 has 2 divisors, whose sum is σ = 1251454400492. Its totient is φ = 1251454400490.

The previous prime is 1251454400489. The next prime is 1251454400543. The reversal of 1251454400491 is 1940044541521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1251454400491 - 2¹ = 1251454400489 is a prime.

It is a super-2 number, since 2×1251454400491² (a number of 25 digits) contains 22 as substring.

Together with 1251454400489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1251454400431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625727200245 + 625727200246.

It is an arithmetic number, because the mean of its divisors is an integer number (625727200246).

Almost surely, 2^{1251454400491} is an apocalyptic number.

1251454400491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251454400491 is an equidigital number, since it uses as much as digits as its factorization.

1251454400491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 115200, while the sum is 40.

The spelling of 1251454400491 in words is "one trillion, two hundred fifty-one billion, four hundred fifty-four million, four hundred thousand, four hundred ninety-one".