16621406 has 4 divisors (see below), whose sum is σ = 24932112. Its totient is φ = 8310702.

The previous prime is 16621391. The next prime is 16621417. The reversal of 16621406 is 60412661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×16621406² = 552542274833672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4155350 + ... + 4155353.

It is an arithmetic number, because the mean of its divisors is an integer number (6233028).

Almost surely, 2^16621406 is an apocalyptic number.

16621406 is a deficient number, since it is larger than the sum of its proper divisors (8310706).

16621406 is an equidigital number, since it uses as much as digits as its factorization.

16621406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8310705.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 16621406 is about 4076.9358591962. The cubic root of 16621406 is about 255.2050433354.

The spelling of 16621406 in words is "sixteen million, six hundred twenty-one thousand, four hundred six".