18261397 has 8 divisors (see below), whose sum is σ = 22767552. Its totient is φ = 14229600.

The previous prime is 18261389. The next prime is 18261407. The reversal of 18261397 is 79316281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18261397 - 2³ = 18261389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18261307) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118504 + ... + 118657.

It is an arithmetic number, because the mean of its divisors is an integer number (2845944).

Almost surely, 2^18261397 is an apocalyptic number.

It is an amenable number.

18261397 is a deficient number, since it is larger than the sum of its proper divisors (4506155).

18261397 is a wasteful number, since it uses less digits than its factorization.

18261397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237179.

The product of its digits is 18144, while the sum is 37.

The square root of 18261397 is about 4273.3355824227. The cubic root of 18261397 is about 263.3366659124.

It can be divided in two parts, 182613 and 97, that added together give a triangular number (182710 = T₆₀₄).

The spelling of 18261397 in words is "eighteen million, two hundred sixty-one thousand, three hundred ninety-seven".