155630561 has 4 divisors (see below), whose sum is σ = 157505712. Its totient is φ = 153755412.

The previous prime is 155630549. The next prime is 155630569. The reversal of 155630561 is 165036551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165036551 = 131 ⋅1259821.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155630561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155630569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 937451 + ... + 937616.

It is an arithmetic number, because the mean of its divisors is an integer number (39376428).

Almost surely, 2^155630561 is an apocalyptic number.

It is an amenable number.

155630561 is a deficient number, since it is larger than the sum of its proper divisors (1875151).

155630561 is an equidigital number, since it uses as much as digits as its factorization.

155630561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1875150.

The product of its (nonzero) digits is 13500, while the sum is 32.

The square root of 155630561 is about 12475.1978341027. The cubic root of 155630561 is about 537.8959747373.

The spelling of 155630561 in words is "one hundred fifty-five million, six hundred thirty thousand, five hundred sixty-one".