126991646 has 4 divisors (see below), whose sum is σ = 190487472. Its totient is φ = 63495822.

The previous prime is 126991621. The next prime is 126991661. The reversal of 126991646 is 646199621.

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

It is a super-2 number, since 2×126991646² = 32253756307578632, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 126991597 and 126991606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31747910 + ... + 31747913.

It is an arithmetic number, because the mean of its divisors is an integer number (47621868).

Almost surely, 2^126991646 is an apocalyptic number.

126991646 is a deficient number, since it is larger than the sum of its proper divisors (63495826).

126991646 is an equidigital number, since it uses as much as digits as its factorization.

126991646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63495825.

The product of its digits is 139968, while the sum is 44.

The square root of 126991646 is about 11269.0570146752. The cubic root of 126991646 is about 502.6415478735.

The spelling of 126991646 in words is "one hundred twenty-six million, nine hundred ninety-one thousand, six hundred forty-six".