1999747540 has 96 divisors (see below), whose sum is σ = 4964843520. Its totient is φ = 662373504.

The previous prime is 1999747537. The next prime is 1999747573. The reversal of 1999747540 is 457479991.

It is a congruent 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, 517897 + ... + 521743.

It is an arithmetic number, because the mean of its divisors is an integer number (51717120).

Almost surely, 2^1999747540 is an apocalyptic number.

1999747540 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 1999747540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2482421760).

1999747540 is an abundant number, since it is smaller than the sum of its proper divisors (2965095980).

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

1999747540 is a wasteful number, since it uses less digits than its factorization.

1999747540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3989 (or 3987 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 55.

The square root of 1999747540 is about 44718.5368723083. The cubic root of 1999747540 is about 1259.8680343861.

The spelling of 1999747540 in words is "one billion, nine hundred ninety-nine million, seven hundred forty-seven thousand, five hundred forty".