126208991 has 4 divisors (see below), whose sum is σ = 126264000. Its totient is φ = 126153984.

The previous prime is 126208987. The next prime is 126208993. The reversal of 126208991 is 199802621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 126208991 - 2² = 126208987 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 (126208993) 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, 23906 + ... + 28703.

It is an arithmetic number, because the mean of its divisors is an integer number (31566000).

Almost surely, 2^126208991 is an apocalyptic number.

126208991 is a deficient number, since it is larger than the sum of its proper divisors (55009).

126208991 is an equidigital number, since it uses as much as digits as its factorization.

126208991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55008.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 126208991 is about 11234.2775023586. The cubic root of 126208991 is about 501.6068187356.

The spelling of 126208991 in words is "one hundred twenty-six million, two hundred eight thousand, nine hundred ninety-one".