126991251 has 12 divisors (see below), whose sum is σ = 183532440. Its totient is φ = 84614400.

The previous prime is 126991223. The next prime is 126991297. The reversal of 126991251 is 152199621.

It is not a de Polignac number, because 126991251 - 2¹⁵ = 126958483 is a prime.

It is a super-2 number, since 2×126991251² = 32253555661090002, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (126991351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24051 + ... + 28851.

It is an arithmetic number, because the mean of its divisors is an integer number (15294370).

Almost surely, 2^126991251 is an apocalyptic number.

126991251 is a deficient number, since it is larger than the sum of its proper divisors (56541189).

126991251 is a wasteful number, since it uses less digits than its factorization.

126991251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7746 (or 7743 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 126991251 is about 11269.0394887941. The cubic root of 126991251 is about 502.6410267274.

The spelling of 126991251 in words is "one hundred twenty-six million, nine hundred ninety-one thousand, two hundred fifty-one".