155241778 has 4 divisors (see below), whose sum is σ = 232862670. Its totient is φ = 77620888.

The previous prime is 155241763. The next prime is 155241781. The reversal of 155241778 is 877142551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 93257649 + 61984129 = 9657^2 + 7873^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 155241778.

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, 38810443 + ... + 38810446.

Almost surely, 2^155241778 is an apocalyptic number.

155241778 is a deficient number, since it is larger than the sum of its proper divisors (77620892).

155241778 is an equidigital number, since it uses as much as digits as its factorization.

155241778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77620891.

The product of its digits is 78400, while the sum is 40.

The square root of 155241778 is about 12459.6058525140. The cubic root of 155241778 is about 537.4476926203.

The spelling of 155241778 in words is "one hundred fifty-five million, two hundred forty-one thousand, seven hundred seventy-eight".