1099010021 has 2 divisors, whose sum is σ = 1099010022. Its totient is φ = 1099010020.

The previous prime is 1099010009. The next prime is 1099010023. The reversal of 1099010021 is 1200109901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 764522500 + 334487521 = 27650^2 + 18289^2 .

It is a cyclic number.

It is not a de Polignac number, because 1099010021 - 2¹⁸ = 1098747877 is a prime.

Together with 1099010023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1099010023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 549505010 + 549505011.

It is an arithmetic number, because the mean of its divisors is an integer number (549505011).

Almost surely, 2^1099010021 is an apocalyptic number.

It is an amenable number.

1099010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1099010021 is an equidigital number, since it uses as much as digits as its factorization.

1099010021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 1099010021 is about 33151.3200491323. The cubic root of 1099010021 is about 1031.9703450430.

Adding to 1099010021 its reverse (1200109901), we get a palindrome (2299119922).

The spelling of 1099010021 in words is "one billion, ninety-nine million, ten thousand, twenty-one".