16121919 has 24 divisors (see below), whose sum is σ = 24667776. Its totient is φ = 9341200.

The previous prime is 16121909. The next prime is 16121921. The reversal of 16121919 is 91912161.

16121919 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16121919 - 2⁵ = 16121887 is a prime.

It is a super-2 number, since 2×16121919² = 519832544485122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16121909) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7384 + ... + 9314.

It is an arithmetic number, because the mean of its divisors is an integer number (1027824).

Almost surely, 2^16121919 is an apocalyptic number.

16121919 is a deficient number, since it is larger than the sum of its proper divisors (8545857).

16121919 is a wasteful number, since it uses less digits than its factorization.

16121919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1979 (or 1968 counting only the distinct ones).

The product of its digits is 972, while the sum is 30.

The square root of 16121919 is about 4015.2109533622. The cubic root of 16121919 is about 252.6226257952.

The spelling of 16121919 in words is "sixteen million, one hundred twenty-one thousand, nine hundred nineteen".