155547661 has 4 divisors (see below), whose sum is σ = 163734400. Its totient is φ = 147360924.

The previous prime is 155547647. The next prime is 155547673. The reversal of 155547661 is 166745551.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155547661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155547631) 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, 4093341 + ... + 4093378.

It is an arithmetic number, because the mean of its divisors is an integer number (40933600).

Almost surely, 2^155547661 is an apocalyptic number.

It is an amenable number.

155547661 is a deficient number, since it is larger than the sum of its proper divisors (8186739).

155547661 is an equidigital number, since it uses as much as digits as its factorization.

155547661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8186738.

The product of its digits is 126000, while the sum is 40.

The square root of 155547661 is about 12471.8747989226. The cubic root of 155547661 is about 537.8004504480.

The spelling of 155547661 in words is "one hundred fifty-five million, five hundred forty-seven thousand, six hundred sixty-one".