155660656649 has 4 divisors (see below), whose sum is σ = 156101622036. Its totient is φ = 155219691264.

The previous prime is 155660656643. The next prime is 155660656663. The reversal of 155660656649 is 946656066551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 121213296649 + 34447360000 = 348157^2 + 185600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155660656649 is a prime.

It is a super-3 number, since 3×155660656649³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155660656643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220482164 + ... + 220482869.

It is an arithmetic number, because the mean of its divisors is an integer number (39025405509).

Almost surely, 2^155660656649 is an apocalyptic number.

It is an amenable number.

155660656649 is a deficient number, since it is larger than the sum of its proper divisors (440965387).

155660656649 is an equidigital number, since it uses as much as digits as its factorization.

155660656649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440965386.

The product of its (nonzero) digits is 34992000, while the sum is 59.

The spelling of 155660656649 in words is "one hundred fifty-five billion, six hundred sixty million, six hundred fifty-six thousand, six hundred forty-nine".