155104991 has 4 divisors (see below), whose sum is σ = 164228832. Its totient is φ = 145981152.

The previous prime is 155104981. The next prime is 155105051. The reversal of 155104991 is 199401551.

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

It is a cyclic number.

It is not a de Polignac number, because 155104991 - 2¹⁸ = 154842847 is a prime.

It is a super-2 number, since 2×155104991² = 48115116466220162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155104921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4561895 + ... + 4561928.

It is an arithmetic number, because the mean of its divisors is an integer number (41057208).

Almost surely, 2^155104991 is an apocalyptic number.

155104991 is a deficient number, since it is larger than the sum of its proper divisors (9123841).

155104991 is an equidigital number, since it uses as much as digits as its factorization.

155104991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9123840.

The product of its (nonzero) digits is 8100, while the sum is 35.

The square root of 155104991 is about 12454.1154242282. The cubic root of 155104991 is about 537.2897938441.

The spelling of 155104991 in words is "one hundred fifty-five million, one hundred four thousand, nine hundred ninety-one".