1909621623 has 16 divisors (see below), whose sum is σ = 3133738496. Its totient is φ = 1007272800.

The previous prime is 1909621613. The next prime is 1909621661. The reversal of 1909621623 is 3261269091.

It is not a de Polignac number, because 1909621623 - 2⁵ = 1909621591 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1909621613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3497203 + ... + 3497748.

It is an arithmetic number, because the mean of its divisors is an integer number (195858656).

Almost surely, 2^1909621623 is an apocalyptic number.

1909621623 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1909621623 is a deficient number, since it is larger than the sum of its proper divisors (1224116873).

1909621623 is a wasteful number, since it uses less digits than its factorization.

1909621623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6994974.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 1909621623 is about 43699.2176474591. The cubic root of 1909621623 is about 1240.6495086285.

The spelling of 1909621623 in words is "one billion, nine hundred nine million, six hundred twenty-one thousand, six hundred twenty-three".