155551601 has 4 divisors (see below), whose sum is σ = 155603172. Its totient is φ = 155500032.

The previous prime is 155551579. The next prime is 155551633. The reversal of 155551601 is 106155551.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 70543201 + 85008400 = 8399^2 + 9220^2 .

It is a cyclic number.

It is not a de Polignac number, because 155551601 - 2¹⁴ = 155535217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155551301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20960 + ... + 27393.

It is an arithmetic number, because the mean of its divisors is an integer number (38900793).

Almost surely, 2^155551601 is an apocalyptic number.

It is an amenable number.

155551601 is a deficient number, since it is larger than the sum of its proper divisors (51571).

155551601 is an equidigital number, since it uses as much as digits as its factorization.

155551601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51570.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 155551601 is about 12472.0327533245. The cubic root of 155551601 is about 537.8049912125.

The spelling of 155551601 in words is "one hundred fifty-five million, five hundred fifty-one thousand, six hundred one".