2009121690 has 64 divisors (see below), whose sum is σ = 5008158720. Its totient is φ = 515457600.

The previous prime is 2009121683. The next prime is 2009121703. The reversal of 2009121690 is 961219002.

It is a happy number.

It is a super-2 number, since 2×2009121690² = 8073139930456912200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71115 + ... + 95265.

It is an arithmetic number, because the mean of its divisors is an integer number (78252480).

Almost surely, 2^2009121690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2009121690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2504079360).

2009121690 is an abundant number, since it is smaller than the sum of its proper divisors (2999037030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2009121690 is a wasteful number, since it uses less digits than its factorization.

2009121690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24267.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 2009121690 is about 44823.2271261229. The cubic root of 2009121690 is about 1261.8335801240.

The spelling of 2009121690 in words is "two billion, nine million, one hundred twenty-one thousand, six hundred ninety".