1011611721 has 4 divisors (see below), whose sum is σ = 1348815632. Its totient is φ = 674407812.

The previous prime is 1011611701. The next prime is 1011611723. The reversal of 1011611721 is 1271161101.

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 1011611721 - 2¹⁷ = 1011480649 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1011611723) 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, 168601951 + ... + 168601956.

It is an arithmetic number, because the mean of its divisors is an integer number (337203908).

Almost surely, 2^1011611721 is an apocalyptic number.

It is an amenable number.

1011611721 is a deficient number, since it is larger than the sum of its proper divisors (337203911).

1011611721 is an equidigital number, since it uses as much as digits as its factorization.

1011611721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337203910.

The product of its (nonzero) digits is 84, while the sum is 21.

The square root of 1011611721 is about 31805.8441328005. The cubic root of 1011611721 is about 1003.8556882283.

Adding to 1011611721 its reverse (1271161101), we get a palindrome (2282772822).

The spelling of 1011611721 in words is "one billion, eleven million, six hundred eleven thousand, seven hundred twenty-one".