16121969 has 4 divisors (see below), whose sum is σ = 16191396. Its totient is φ = 16052544.

The previous prime is 16121921. The next prime is 16121971. The reversal of 16121969 is 96912161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96912161 = 59 ⋅1642579.

It can be written as a sum of positive squares in 2 ways, for example, as 7360369 + 8761600 = 2713^2 + 2960^2 .

It is a cyclic number.

It is not a de Polignac number, because 16121969 - 2⁸ = 16121713 is a prime.

It is a super-2 number, since 2×16121969² = 519835768873922, which contains 22 as substring.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 34364 + ... + 34829.

It is an arithmetic number, because the mean of its divisors is an integer number (4047849).

Almost surely, 2^16121969 is an apocalyptic number.

It is an amenable number.

16121969 is a deficient number, since it is larger than the sum of its proper divisors (69427).

16121969 is an equidigital number, since it uses as much as digits as its factorization.

16121969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69426.

The product of its digits is 5832, while the sum is 35.

The square root of 16121969 is about 4015.2171796803. The cubic root of 16121969 is about 252.6228869535.

The spelling of 16121969 in words is "sixteen million, one hundred twenty-one thousand, nine hundred sixty-nine".