16221497 has 4 divisors (see below), whose sum is σ = 17075280. Its totient is φ = 15367716.

The previous prime is 16221493. The next prime is 16221523. The reversal of 16221497 is 79412261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16221497 - 2² = 16221493 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16221493) 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, 426863 + ... + 426900.

It is an arithmetic number, because the mean of its divisors is an integer number (4268820).

Almost surely, 2^16221497 is an apocalyptic number.

It is an amenable number.

16221497 is a deficient number, since it is larger than the sum of its proper divisors (853783).

16221497 is an equidigital number, since it uses as much as digits as its factorization.

16221497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 853782.

The product of its digits is 6048, while the sum is 32.

The square root of 16221497 is about 4027.5919604647. The cubic root of 16221497 is about 253.1416715535.

The spelling of 16221497 in words is "sixteen million, two hundred twenty-one thousand, four hundred ninety-seven".