1089210021 has 4 divisors (see below), whose sum is σ = 1452280032. Its totient is φ = 726140012.

The previous prime is 1089210019. The next prime is 1089210071. The reversal of 1089210021 is 1200129801.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1089210021 - 2¹ = 1089210019 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1089209973 and 1089210000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1089210071) 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, 181535001 + ... + 181535006.

It is an arithmetic number, because the mean of its divisors is an integer number (363070008).

Almost surely, 2^1089210021 is an apocalyptic number.

It is an amenable number.

1089210021 is a deficient number, since it is larger than the sum of its proper divisors (363070011).

1089210021 is an equidigital number, since it uses as much as digits as its factorization.

1089210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363070010.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 1089210021 is about 33003.1819829543. The cubic root of 1089210021 is about 1028.8937823441.

Adding to 1089210021 its reverse (1200129801), we get a palindrome (2289339822).

It can be divided in two parts, 108 and 9210021, that added together give a palindrome (9210129).

The spelling of 1089210021 in words is "one billion, eighty-nine million, two hundred ten thousand, twenty-one".