1021991216 has 10 divisors (see below), whose sum is σ = 1980108012. Its totient is φ = 510995600.

The previous prime is 1021991213. The next prime is 1021991221. The reversal of 1021991216 is 6121991201.

1021991216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (1021991213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31937210 + ... + 31937241.

Almost surely, 2^1021991216 is an apocalyptic number.

1021991216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1021991216 is a deficient number, since it is larger than the sum of its proper divisors (958116796).

1021991216 is an equidigital number, since it uses as much as digits as its factorization.

1021991216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63874459 (or 63874453 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 1021991216 is about 31968.5973417665. The cubic root of 1021991216 is about 1007.2773175158.

The spelling of 1021991216 in words is "one billion, twenty-one million, nine hundred ninety-one thousand, two hundred sixteen".