16220391 has 8 divisors (see below), whose sum is σ = 23593344. Its totient is φ = 9830520.

The previous prime is 16220383. The next prime is 16220401. The reversal of 16220391 is 19302261.

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

It is not a de Polignac number, because 16220391 - 2³ = 16220383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16220371) 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, 245731 + ... + 245796.

It is an arithmetic number, because the mean of its divisors is an integer number (2949168).

Almost surely, 2^16220391 is an apocalyptic number.

16220391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

16220391 is a deficient number, since it is larger than the sum of its proper divisors (7372953).

16220391 is a wasteful number, since it uses less digits than its factorization.

16220391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491541.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 16220391 is about 4027.4546552382. The cubic root of 16220391 is about 253.1359182609.

The spelling of 16220391 in words is "sixteen million, two hundred twenty thousand, three hundred ninety-one".