126155921 has 4 divisors (see below), whose sum is σ = 126407232. Its totient is φ = 125904612.

The previous prime is 126155891. The next prime is 126155941. The reversal of 126155921 is 129551621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 129551621 = 1129 ⋅114749.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-126155921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126155941) 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, 124901 + ... + 125906.

It is an arithmetic number, because the mean of its divisors is an integer number (31601808).

Almost surely, 2^126155921 is an apocalyptic number.

It is an amenable number.

126155921 is a deficient number, since it is larger than the sum of its proper divisors (251311).

126155921 is an equidigital number, since it uses as much as digits as its factorization.

126155921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251310.

The product of its digits is 5400, while the sum is 32.

The square root of 126155921 is about 11231.9152863614. The cubic root of 126155921 is about 501.5365014898.

The spelling of 126155921 in words is "one hundred twenty-six million, one hundred fifty-five thousand, nine hundred twenty-one".