1017920421 has 24 divisors (see below), whose sum is σ = 1768819520. Its totient is φ = 551054016.

The previous prime is 1017920417. The next prime is 1017920443. The reversal of 1017920421 is 1240297101.

It is not a de Polignac number, because 1017920421 - 2² = 1017920417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1017920411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 424000 + ... + 426393.

Almost surely, 2^1017920421 is an apocalyptic number.

It is an amenable number.

1017920421 is a deficient number, since it is larger than the sum of its proper divisors (750899099).

1017920421 is a wasteful number, since it uses less digits than its factorization.

1017920421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850425 (or 850422 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 1017920421 is about 31904.8651619154. The cubic root of 1017920421 is about 1005.9381423363.

The spelling of 1017920421 in words is "one billion, seventeen million, nine hundred twenty thousand, four hundred twenty-one".