155661554 has 8 divisors (see below), whose sum is σ = 247227228. Its totient is φ = 73252480.

The previous prime is 155661551. The next prime is 155661557. The reversal of 155661554 is 455166551.

It is a happy number.

155661554 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (155661551) and next prime (155661557).

It can be written as a sum of positive squares in 2 ways, for example, as 141015625 + 14645929 = 11875^2 + 3827^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (155661551) 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, 2289107 + ... + 2289174.

Almost surely, 2^155661554 is an apocalyptic number.

155661554 is a deficient number, since it is larger than the sum of its proper divisors (91565674).

155661554 is a wasteful number, since it uses less digits than its factorization.

155661554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4578300.

The product of its digits is 90000, while the sum is 38.

The square root of 155661554 is about 12476.4399569749. The cubic root of 155661554 is about 537.9316787433.

The spelling of 155661554 in words is "one hundred fifty-five million, six hundred sixty-one thousand, five hundred fifty-four".