126992021 has 4 divisors (see below), whose sum is σ = 136760652. Its totient is φ = 117223392.

The previous prime is 126991961. The next prime is 126992051. The reversal of 126992021 is 120299621.

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

It can be written as a sum of positive squares in 2 ways, for example, as 59505796 + 67486225 = 7714^2 + 8215^2 .

It is not a de Polignac number, because 126992021 - 2¹⁴ = 126975637 is a prime.

It is a super-2 number, since 2×126992021² = 32253946795328882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126992051) 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, 4884296 + ... + 4884321.

It is an arithmetic number, because the mean of its divisors is an integer number (34190163).

Almost surely, 2^126992021 is an apocalyptic number.

It is an amenable number.

126992021 is a deficient number, since it is larger than the sum of its proper divisors (9768631).

126992021 is an equidigital number, since it uses as much as digits as its factorization.

126992021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9768630.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 126992021 is about 11269.0736531447. The cubic root of 126992021 is about 502.6420426315.

The spelling of 126992021 in words is "one hundred twenty-six million, nine hundred ninety-two thousand, twenty-one".