1999581064 has 16 divisors (see below), whose sum is σ = 4037615820. Its totient is φ = 922883520.

The previous prime is 1999581053. The next prime is 1999581083. The reversal of 1999581064 is 4601859991.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1994336964 + 5244100 = 44658^2 + 2290^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9613267 + ... + 9613474.

Almost surely, 2^1999581064 is an apocalyptic number.

It is an amenable number.

1999581064 is an abundant number, since it is smaller than the sum of its proper divisors (2038034756).

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

1999581064 is a wasteful number, since it uses less digits than its factorization.

1999581064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19226760 (or 19226756 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 52.

The square root of 1999581064 is about 44716.6754578200. The cubic root of 1999581064 is about 1259.8330727043.

The spelling of 1999581064 in words is "one billion, nine hundred ninety-nine million, five hundred eighty-one thousand, sixty-four".