16622991 has 72 divisors (see below), whose sum is σ = 32183424. Its totient is φ = 8029440.

The previous prime is 16622989. The next prime is 16622993. The reversal of 16622991 is 19922661.

It is an interprime number because it is at equal distance from previous prime (16622989) and next prime (16622993).

It is not a de Polignac number, because 16622991 - 2¹ = 16622989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16622993) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 200236 + ... + 200318.

It is an arithmetic number, because the mean of its divisors is an integer number (446992).

Almost surely, 2^16622991 is an apocalyptic number.

16622991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

16622991 is a deficient number, since it is larger than the sum of its proper divisors (15560433).

16622991 is a wasteful number, since it uses less digits than its factorization.

16622991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 121 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 16622991 is about 4077.1302407453. The cubic root of 16622991 is about 255.2131551068.

The spelling of 16622991 in words is "sixteen million, six hundred twenty-two thousand, nine hundred ninety-one".