127749721 has 8 divisors (see below), whose sum is σ = 139637088. Its totient is φ = 115908000.

The previous prime is 127749719. The next prime is 127749731. The reversal of 127749721 is 127947721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 127749721 - 2¹ = 127749719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127749701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5415 + ... + 16876.

It is an arithmetic number, because the mean of its divisors is an integer number (17454636).

Almost surely, 2^127749721 is an apocalyptic number.

127749721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

127749721 is a deficient number, since it is larger than the sum of its proper divisors (11887367).

127749721 is a wasteful number, since it uses less digits than its factorization.

127749721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22823.

The product of its digits is 49392, while the sum is 40.

The square root of 127749721 is about 11302.6422132172. The cubic root of 127749721 is about 503.6397350338.

The spelling of 127749721 in words is "one hundred twenty-seven million, seven hundred forty-nine thousand, seven hundred twenty-one".