1021996291 has 4 divisors (see below), whose sum is σ = 1022280472. Its totient is φ = 1021712112.

The previous prime is 1021996273. The next prime is 1021996303. The reversal of 1021996291 is 1926991201.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1021996291 - 2¹¹ = 1021994243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021996211) 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, 136626 + ... + 143911.

It is an arithmetic number, because the mean of its divisors is an integer number (255570118).

Almost surely, 2^1021996291 is an apocalyptic number.

1021996291 is a deficient number, since it is larger than the sum of its proper divisors (284181).

1021996291 is an equidigital number, since it uses as much as digits as its factorization.

1021996291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284180.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 1021996291 is about 31968.6767164360. The cubic root of 1021996291 is about 1007.2789848243.

The spelling of 1021996291 in words is "one billion, twenty-one million, nine hundred ninety-six thousand, two hundred ninety-one".