1991540430 has 48 divisors (see below), whose sum is σ = 5648735664. Its totient is φ = 482797440.

The previous prime is 1991540413. The next prime is 1991540449. The reversal of 1991540430 is 340451991.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1004839 + ... + 1006818.

It is an arithmetic number, because the mean of its divisors is an integer number (117681993).

Almost surely, 2^1991540430 is an apocalyptic number.

1991540430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1991540430 is an abundant number, since it is smaller than the sum of its proper divisors (3657195234).

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

1991540430 is a wasteful number, since it uses less digits than its factorization.

1991540430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2011681 (or 2011678 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 1991540430 is about 44626.6784558295. The cubic root of 1991540430 is about 1258.1421410123.

The spelling of 1991540430 in words is "one billion, nine hundred ninety-one million, five hundred forty thousand, four hundred thirty".