1011994021 has 8 divisors (see below), whose sum is σ = 1037570688. Its totient is φ = 986460000.

The previous prime is 1011994013. The next prime is 1011994033. The reversal of 1011994021 is 1204991101.

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

It is not a de Polignac number, because 1011994021 - 2³ = 1011994013 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 (1011194021) 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, 40446 + ... + 60496.

It is an arithmetic number, because the mean of its divisors is an integer number (129696336).

Almost surely, 2^1011994021 is an apocalyptic number.

It is an amenable number.

1011994021 is a deficient number, since it is larger than the sum of its proper divisors (25576667).

1011994021 is a wasteful number, since it uses less digits than its factorization.

1011994021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21323.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 1011994021 is about 31811.8534669076. The cubic root of 1011994021 is about 1003.9821286031.

The spelling of 1011994021 in words is "one billion, eleven million, nine hundred ninety-four thousand, twenty-one".