155681489 has 4 divisors (see below), whose sum is σ = 156581556. Its totient is φ = 154781424.

The previous prime is 155681467. The next prime is 155681507. The reversal of 155681489 is 984186551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 984186551 = 21611 ⋅45541.

It can be written as a sum of positive squares in 2 ways, for example, as 82664464 + 73017025 = 9092^2 + 8545^2 .

It is a cyclic number.

It is not a de Polignac number, because 155681489 - 2⁸ = 155681233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155681389) 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, 449774 + ... + 450119.

It is an arithmetic number, because the mean of its divisors is an integer number (39145389).

Almost surely, 2^155681489 is an apocalyptic number.

It is an amenable number.

155681489 is a deficient number, since it is larger than the sum of its proper divisors (900067).

155681489 is an equidigital number, since it uses as much as digits as its factorization.

155681489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900066.

The product of its digits is 345600, while the sum is 47.

The square root of 155681489 is about 12477.2388371787. The cubic root of 155681489 is about 537.9546414038.

The spelling of 155681489 in words is "one hundred fifty-five million, six hundred eighty-one thousand, four hundred eighty-nine".