18949321 has 2 divisors, whose sum is σ = 18949322. Its totient is φ = 18949320.

The previous prime is 18949313. The next prime is 18949331. The reversal of 18949321 is 12394981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18020025 + 929296 = 4245^2 + 964^2 .

It is a cyclic number.

It is not a de Polignac number, because 18949321 - 2³ = 18949313 is a prime.

It is a super-2 number, since 2×18949321² = 718153532722082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18949331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9474660 + 9474661.

It is an arithmetic number, because the mean of its divisors is an integer number (9474661).

Almost surely, 2^18949321 is an apocalyptic number.

It is an amenable number.

18949321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18949321 is an equidigital number, since it uses as much as digits as its factorization.

18949321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 37.

The square root of 18949321 is about 4353.0817819104. The cubic root of 18949321 is about 266.6027046247.

The spelling of 18949321 in words is "eighteen million, nine hundred forty-nine thousand, three hundred twenty-one".