51661252878427 has 2 divisors, whose sum is σ = 51661252878428. Its totient is φ = 51661252878426.

The previous prime is 51661252878413. The next prime is 51661252878589. The reversal of 51661252878427 is 72487825216615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51661252878427 - 2⁷ = 51661252878299 is a prime.

It is not a weakly prime, because it can be changed into another prime (51661252878407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25830626439213 + 25830626439214.

It is an arithmetic number, because the mean of its divisors is an integer number (25830626439214).

Almost surely, 2^{51661252878427} is an apocalyptic number.

51661252878427 is a deficient number, since it is larger than the sum of its proper divisors (1).

51661252878427 is an equidigital number, since it uses as much as digits as its factorization.

51661252878427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90316800, while the sum is 64.

The spelling of 51661252878427 in words is "fifty-one trillion, six hundred sixty-one billion, two hundred fifty-two million, eight hundred seventy-eight thousand, four hundred twenty-seven".