155207217 has 32 divisors (see below), whose sum is σ = 235255680. Its totient is φ = 90155520.

The previous prime is 155207209. The next prime is 155207233. The reversal of 155207217 is 712702551.

It is not a de Polignac number, because 155207217 - 2³ = 155207209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155200217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 149733 + ... + 150765.

It is an arithmetic number, because the mean of its divisors is an integer number (7351740).

Almost surely, 2^155207217 is an apocalyptic number.

It is an amenable number.

155207217 is a deficient number, since it is larger than the sum of its proper divisors (80048463).

155207217 is a wasteful number, since it uses less digits than its factorization.

155207217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233.

The product of its (nonzero) digits is 4900, while the sum is 30.

The square root of 155207217 is about 12458.2188534317. The cubic root of 155207217 is about 537.4078062174.

Adding to 155207217 its reverse (712702551), we get a palindrome (867909768).

The spelling of 155207217 in words is "one hundred fifty-five million, two hundred seven thousand, two hundred seventeen".