155345564021 has 2 divisors, whose sum is σ = 155345564022. Its totient is φ = 155345564020.

The previous prime is 155345563957. The next prime is 155345564071. The reversal of 155345564021 is 120465543551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133996263025 + 21349300996 = 366055^2 + 146114^2 .

It is a cyclic number.

It is not a de Polignac number, because 155345564021 - 2⁶ = 155345563957 is a prime.

It is a super-2 number, since 2×155345564021² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 155345564021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155345564071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77672782010 + 77672782011.

It is an arithmetic number, because the mean of its divisors is an integer number (77672782011).

Almost surely, 2^155345564021 is an apocalyptic number.

It is an amenable number.

155345564021 is a deficient number, since it is larger than the sum of its proper divisors (1).

155345564021 is an equidigital number, since it uses as much as digits as its factorization.

155345564021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360000, while the sum is 41.

The spelling of 155345564021 in words is "one hundred fifty-five billion, three hundred forty-five million, five hundred sixty-four thousand, twenty-one".