1909261420 has 72 divisors (see below), whose sum is σ = 4526402832. Its totient is φ = 675480960.

The previous prime is 1909261373. The next prime is 1909261421. The reversal of 1909261420 is 241629091.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1909261421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78879 + ... + 100201.

It is an arithmetic number, because the mean of its divisors is an integer number (62866706).

Almost surely, 2^1909261420 is an apocalyptic number.

1909261420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1909261420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2263201416).

1909261420 is an abundant number, since it is smaller than the sum of its proper divisors (2617141412).

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

1909261420 is a wasteful number, since it uses less digits than its factorization.

1909261420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21391 (or 21378 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 1909261420 is about 43695.0960635172. The cubic root of 1909261420 is about 1240.5714977509.

The spelling of 1909261420 in words is "one billion, nine hundred nine million, two hundred sixty-one thousand, four hundred twenty".