126121165 has 4 divisors (see below), whose sum is σ = 151345404. Its totient is φ = 100896928.

The previous prime is 126121141. The next prime is 126121169. The reversal of 126121165 is 561121621.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 561121621 = 8893 ⋅63097.

It can be written as a sum of positive squares in 2 ways, for example, as 56265001 + 69856164 = 7501^2 + 8358^2 .

It is a cyclic number.

It is not a de Polignac number, because 126121165 - 2⁵ = 126121133 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 (126121169) 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, 12612112 + ... + 12612121.

It is an arithmetic number, because the mean of its divisors is an integer number (37836351).

Almost surely, 2^126121165 is an apocalyptic number.

It is an amenable number.

126121165 is a deficient number, since it is larger than the sum of its proper divisors (25224239).

126121165 is an equidigital number, since it uses as much as digits as its factorization.

126121165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25224238.

The product of its digits is 720, while the sum is 25.

The square root of 126121165 is about 11230.3679815044. The cubic root of 126121165 is about 501.4904394328.

Adding to 126121165 its reverse (561121621), we get a palindrome (687242786).

The spelling of 126121165 in words is "one hundred twenty-six million, one hundred twenty-one thousand, one hundred sixty-five".