126165221 has 16 divisors (see below), whose sum is σ = 157605504. Its totient is φ = 98328384.

The previous prime is 126165217. The next prime is 126165251. The reversal of 126165221 is 122561621.

It is not a de Polignac number, because 126165221 - 2² = 126165217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126165251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4250 + ... + 16443.

It is an arithmetic number, because the mean of its divisors is an integer number (9850344).

Almost surely, 2^126165221 is an apocalyptic number.

It is an amenable number.

126165221 is a deficient number, since it is larger than the sum of its proper divisors (31440283).

126165221 is a wasteful number, since it uses less digits than its factorization.

126165221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20780.

The product of its digits is 1440, while the sum is 26.

The square root of 126165221 is about 11232.3292775809. The cubic root of 126165221 is about 501.5488253263.

The spelling of 126165221 in words is "one hundred twenty-six million, one hundred sixty-five thousand, two hundred twenty-one".