18802921 has 2 divisors, whose sum is σ = 18802922. Its totient is φ = 18802920.

The previous prime is 18802909. The next prime is 18802943. The reversal of 18802921 is 12920881.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18800896 + 2025 = 4336^2 + 45^2 .

It is a cyclic number.

It is not a de Polignac number, because 18802921 - 2¹⁵ = 18770153 is a prime.

It is not a weakly prime, because it can be changed into another prime (18812921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9401460 + 9401461.

It is an arithmetic number, because the mean of its divisors is an integer number (9401461).

Almost surely, 2^18802921 is an apocalyptic number.

It is an amenable number.

18802921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18802921 is an equidigital number, since it uses as much as digits as its factorization.

18802921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 18802921 is about 4336.2335038602. The cubic root of 18802921 is about 265.9143495322.

The spelling of 18802921 in words is "eighteen million, eight hundred two thousand, nine hundred twenty-one".