126720649 has 4 divisors (see below), whose sum is σ = 138240720. Its totient is φ = 115200580.

The previous prime is 126720647. The next prime is 126720673. The reversal of 126720649 is 946027621.

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 126720649 - 2¹ = 126720647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126720647) 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, 5760019 + ... + 5760040.

It is an arithmetic number, because the mean of its divisors is an integer number (34560180).

Almost surely, 2^126720649 is an apocalyptic number.

It is an amenable number.

126720649 is a deficient number, since it is larger than the sum of its proper divisors (11520071).

126720649 is a wasteful number, since it uses less digits than its factorization.

126720649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11520070.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 126720649 is about 11257.0266500528. The cubic root of 126720649 is about 502.2837517414.

The spelling of 126720649 in words is "one hundred twenty-six million, seven hundred twenty thousand, six hundred forty-nine".