155661211 has 2 divisors, whose sum is σ = 155661212. Its totient is φ = 155661210.

The previous prime is 155661193. The next prime is 155661269. The reversal of 155661211 is 112166551.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155661211 - 2²³ = 147272603 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155661211.

It is not a weakly prime, because it can be changed into another prime (155661511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77830605 + 77830606.

It is an arithmetic number, because the mean of its divisors is an integer number (77830606).

Almost surely, 2^155661211 is an apocalyptic number.

155661211 is a deficient number, since it is larger than the sum of its proper divisors (1).

155661211 is an equidigital number, since it uses as much as digits as its factorization.

155661211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1800, while the sum is 28.

The square root of 155661211 is about 12476.4262110590. The cubic root of 155661211 is about 537.9312836324.

The spelling of 155661211 in words is "one hundred fifty-five million, six hundred sixty-one thousand, two hundred eleven".