155102809 has 4 divisors (see below), whose sum is σ = 157645540. Its totient is φ = 152560080.

The previous prime is 155102807. The next prime is 155102839. The reversal of 155102809 is 908201551.

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 5774409 + 149328400 = 2403^2 + 12220^2 .

It is a cyclic number.

It is not a de Polignac number, because 155102809 - 2¹ = 155102807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155102803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1271274 + ... + 1271395.

It is an arithmetic number, because the mean of its divisors is an integer number (39411385).

Almost surely, 2^155102809 is an apocalyptic number.

It is an amenable number.

155102809 is a deficient number, since it is larger than the sum of its proper divisors (2542731).

155102809 is an equidigital number, since it uses as much as digits as its factorization.

155102809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2542730.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 155102809 is about 12454.0278223553. The cubic root of 155102809 is about 537.2872743210.

The spelling of 155102809 in words is "one hundred fifty-five million, one hundred two thousand, eight hundred nine".