155381242 has 4 divisors (see below), whose sum is σ = 233071866. Its totient is φ = 77690620.

The previous prime is 155381209. The next prime is 155381243. The reversal of 155381242 is 242183551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242183551 = 241 ⋅1004911.

It can be written as a sum of positive squares in only one way, i.e., 122788561 + 32592681 = 11081^2 + 5709^2 .

It is not an unprimeable number, because it can be changed into a prime (155381243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38845309 + ... + 38845312.

Almost surely, 2^155381242 is an apocalyptic number.

155381242 is a deficient number, since it is larger than the sum of its proper divisors (77690624).

155381242 is an equidigital number, since it uses as much as digits as its factorization.

155381242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77690623.

The product of its digits is 9600, while the sum is 31.

The square root of 155381242 is about 12465.2012418573. The cubic root of 155381242 is about 537.6085861023.

The spelling of 155381242 in words is "one hundred fifty-five million, three hundred eighty-one thousand, two hundred forty-two".