155825378581 has 2 divisors, whose sum is σ = 155825378582. Its totient is φ = 155825378580.

The previous prime is 155825378567. The next prime is 155825378633. The reversal of 155825378581 is 185873528551.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151756214481 + 4069164100 = 389559^2 + 63790^2 .

It is a cyclic number.

It is not a de Polignac number, because 155825378581 - 2⁷ = 155825378453 is a prime.

It is a super-2 number, since 2×155825378581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155825378521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77912689290 + 77912689291.

It is an arithmetic number, because the mean of its divisors is an integer number (77912689291).

Almost surely, 2^155825378581 is an apocalyptic number.

It is an amenable number.

155825378581 is a deficient number, since it is larger than the sum of its proper divisors (1).

155825378581 is an equidigital number, since it uses as much as digits as its factorization.

155825378581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440000, while the sum is 58.

The spelling of 155825378581 in words is "one hundred fifty-five billion, eight hundred twenty-five million, three hundred seventy-eight thousand, five hundred eighty-one".