126991019 has 4 divisors (see below), whose sum is σ = 128730696. Its totient is φ = 125251344.

The previous prime is 126990989. The next prime is 126991031. The reversal of 126991019 is 910199621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 910199621 = 853 ⋅1067057.

It is a cyclic number.

It is not a de Polignac number, because 126991019 - 2¹⁶ = 126925483 is a prime.

It is a super-3 number, since 3×126991019³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126991099) 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, 869729 + ... + 869874.

It is an arithmetic number, because the mean of its divisors is an integer number (32182674).

Almost surely, 2^126991019 is an apocalyptic number.

126991019 is a deficient number, since it is larger than the sum of its proper divisors (1739677).

126991019 is an equidigital number, since it uses as much as digits as its factorization.

126991019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739676.

The product of its (nonzero) digits is 8748, while the sum is 38.

The square root of 126991019 is about 11269.0291950993. The cubic root of 126991019 is about 502.6407206360.

The spelling of 126991019 in words is "one hundred twenty-six million, nine hundred ninety-one thousand, nineteen".