1999263780 has 72 divisors (see below), whose sum is σ = 6260077824. Its totient is φ = 515937600.

The previous prime is 1999263779. The next prime is 1999263787. The reversal of 1999263780 is 873629991.

It is not an unprimeable number, because it can be changed into a prime (1999263787) 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, 173566 + ... + 184725.

Almost surely, 2^1999263780 is an apocalyptic number.

1999263780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1999263780 is an abundant number, since it is smaller than the sum of its proper divisors (4260814044).

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

1999263780 is a wasteful number, since it uses less digits than its factorization.

1999263780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358337 (or 358332 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The square root of 1999263780 is about 44713.1276025285. The cubic root of 1999263780 is about 1259.7664344089.

The spelling of 1999263780 in words is "one billion, nine hundred ninety-nine million, two hundred sixty-three thousand, seven hundred eighty".