16121663 has 4 divisors (see below), whose sum is σ = 16278288. Its totient is φ = 15965040.

The previous prime is 16121657. The next prime is 16121681. The reversal of 16121663 is 36612161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36612161 = 439 ⋅83399.

It is a cyclic number.

It is not a de Polignac number, because 16121663 - 2⁴ = 16121647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16121363) 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, 78158 + ... + 78363.

It is an arithmetic number, because the mean of its divisors is an integer number (4069572).

Almost surely, 2^16121663 is an apocalyptic number.

16121663 is a deficient number, since it is larger than the sum of its proper divisors (156625).

16121663 is a wasteful number, since it uses less digits than its factorization.

16121663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156624.

The product of its digits is 1296, while the sum is 26.

The square root of 16121663 is about 4015.1790744623. The cubic root of 16121663 is about 252.6212886563.

The spelling of 16121663 in words is "sixteen million, one hundred twenty-one thousand, six hundred sixty-three".