1855420613537 has 2 divisors, whose sum is σ = 1855420613538. Its totient is φ = 1855420613536.

The previous prime is 1855420613503. The next prime is 1855420613539. The reversal of 1855420613537 is 7353160245581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1628645601856 + 226775011681 = 1276184^2 + 476209^2 .

It is a cyclic number.

It is not a de Polignac number, because 1855420613537 - 2³⁸ = 1580542706593 is a prime.

It is a super-3 number, since 3×1855420613537³ (a number of 38 digits) contains 333 as substring.

Together with 1855420613539, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1855420613539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 927710306768 + 927710306769.

It is an arithmetic number, because the mean of its divisors is an integer number (927710306769).

Almost surely, 2^{1855420613537} is an apocalyptic number.

It is an amenable number.

1855420613537 is a deficient number, since it is larger than the sum of its proper divisors (1).

1855420613537 is an equidigital number, since it uses as much as digits as its factorization.

1855420613537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024000, while the sum is 50.

The spelling of 1855420613537 in words is "one trillion, eight hundred fifty-five billion, four hundred twenty million, six hundred thirteen thousand, five hundred thirty-seven".