1861622850557 has 2 divisors, whose sum is σ = 1861622850558. Its totient is φ = 1861622850556.

The previous prime is 1861622850547. The next prime is 1861622850569. The reversal of 1861622850557 is 7550582261681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1655787327076 + 205835523481 = 1286774^2 + 453691^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861622850557 - 2²² = 1861618656253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861622850547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930811425278 + 930811425279.

It is an arithmetic number, because the mean of its divisors is an integer number (930811425279).

Almost surely, 2^{1861622850557} is an apocalyptic number.

It is an amenable number.

1861622850557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861622850557 is an equidigital number, since it uses as much as digits as its factorization.

1861622850557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064000, while the sum is 56.

The spelling of 1861622850557 in words is "one trillion, eight hundred sixty-one billion, six hundred twenty-two million, eight hundred fifty thousand, five hundred fifty-seven".