155231661 has 8 divisors (see below), whose sum is σ = 222896800. Its totient is φ = 95527152.

The previous prime is 155231651. The next prime is 155231683. The reversal of 155231661 is 166132551.

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

It is not a de Polignac number, because 155231661 - 2⁶ = 155231597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155231651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1990111 + ... + 1990188.

It is an arithmetic number, because the mean of its divisors is an integer number (27862100).

Almost surely, 2^155231661 is an apocalyptic number.

It is an amenable number.

155231661 is a deficient number, since it is larger than the sum of its proper divisors (67665139).

155231661 is a wasteful number, since it uses less digits than its factorization.

155231661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980315.

The product of its digits is 5400, while the sum is 30.

The square root of 155231661 is about 12459.1998539232. The cubic root of 155231661 is about 537.4360173344.

The spelling of 155231661 in words is "one hundred fifty-five million, two hundred thirty-one thousand, six hundred sixty-one".