126581997 has 4 divisors (see below), whose sum is σ = 168776000. Its totient is φ = 84387996.

The previous prime is 126581969. The next prime is 126581999. The reversal of 126581997 is 799185621.

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.

It is not a de Polignac number, because 126581997 - 2¹¹ = 126579949 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 (126581999) 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, 21096997 + ... + 21097002.

It is an arithmetic number, because the mean of its divisors is an integer number (42194000).

Almost surely, 2^126581997 is an apocalyptic number.

It is an amenable number.

126581997 is a deficient number, since it is larger than the sum of its proper divisors (42194003).

126581997 is an equidigital number, since it uses as much as digits as its factorization.

126581997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42194002.

The product of its digits is 272160, while the sum is 48.

The square root of 126581997 is about 11250.8664999635. The cubic root of 126581997 is about 502.1004928363.

The spelling of 126581997 in words is "one hundred twenty-six million, five hundred eighty-one thousand, nine hundred ninety-seven".