1240111721 has 4 divisors (see below), whose sum is σ = 1273628292. Its totient is φ = 1206595152.

The previous prime is 1240111711. The next prime is 1240111727. The reversal of 1240111721 is 1271110421.

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 899340121 + 340771600 = 29989^2 + 18460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1240111721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1240111693 and 1240111702.

It is not an unprimeable number, because it can be changed into a prime (1240111727) 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, 16758230 + ... + 16758303.

It is an arithmetic number, because the mean of its divisors is an integer number (318407073).

Almost surely, 2^1240111721 is an apocalyptic number.

It is an amenable number.

1240111721 is a deficient number, since it is larger than the sum of its proper divisors (33516571).

1240111721 is an equidigital number, since it uses as much as digits as its factorization.

1240111721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33516570.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 1240111721 is about 35215.2200191906. The cubic root of 1240111721 is about 1074.3693350770.

The spelling of 1240111721 in words is "one billion, two hundred forty million, one hundred eleven thousand, seven hundred twenty-one".