18223913 has 2 divisors, whose sum is σ = 18223914. Its totient is φ = 18223912.

The previous prime is 18223903. The next prime is 18223927. The reversal of 18223913 is 31932281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16297369 + 1926544 = 4037^2 + 1388^2 .

It is an emirp because it is prime and its reverse (31932281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18223913 - 2⁸ = 18223657 is a prime.

It is a super-2 number, since 2×18223913² = 664222010063138, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18223903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9111956 + 9111957.

It is an arithmetic number, because the mean of its divisors is an integer number (9111957).

Almost surely, 2^18223913 is an apocalyptic number.

It is an amenable number.

18223913 is a deficient number, since it is larger than the sum of its proper divisors (1).

18223913 is an equidigital number, since it uses as much as digits as its factorization.

18223913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 18223913 is about 4268.9475283728. The cubic root of 18223913 is about 263.1563643890.

The spelling of 18223913 in words is "eighteen million, two hundred twenty-three thousand, nine hundred thirteen".