155231642 has 4 divisors (see below), whose sum is σ = 232847466. Its totient is φ = 77615820.

The previous prime is 155231639. The next prime is 155231651. The reversal of 155231642 is 246132551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 246132551 = 7 ⋅35161793.

It can be written as a sum of positive squares in only one way, i.e., 137851081 + 17380561 = 11741^2 + 4169^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38807909 + ... + 38807912.

Almost surely, 2^155231642 is an apocalyptic number.

155231642 is a deficient number, since it is larger than the sum of its proper divisors (77615824).

155231642 is an equidigital number, since it uses as much as digits as its factorization.

155231642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77615823.

The product of its digits is 7200, while the sum is 29.

The square root of 155231642 is about 12459.1990914344. The cubic root of 155231642 is about 537.4359954074.

Subtracting 155231642 from its reverse (246132551), we obtain a palindrome (90900909).

The spelling of 155231642 in words is "one hundred fifty-five million, two hundred thirty-one thousand, six hundred forty-two".