919417721 has 4 divisors (see below), whose sum is σ = 931056000. Its totient is φ = 907779444.

The previous prime is 919417717. The next prime is 919417753. The reversal of 919417721 is 127714919.

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, and also an emirpimes, since its reverse is a distinct semiprime: 127714919 = 1039 ⋅122921.

It is a cyclic number.

It is not a de Polignac number, because 919417721 - 2² = 919417717 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 (919417021) 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, 5819021 + ... + 5819178.

It is an arithmetic number, because the mean of its divisors is an integer number (232764000).

Almost surely, 2^919417721 is an apocalyptic number.

It is an amenable number.

919417721 is a deficient number, since it is larger than the sum of its proper divisors (11638279).

919417721 is a wasteful number, since it uses less digits than its factorization.

919417721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11638278.

The product of its digits is 31752, while the sum is 41.

The square root of 919417721 is about 30321.9016718939. The cubic root of 919417721 is about 972.3835952161.

The spelling of 919417721 in words is "nine hundred nineteen million, four hundred seventeen thousand, seven hundred twenty-one".