1999065501 has 24 divisors (see below), whose sum is σ = 3051004320. Its totient is φ = 1307556432.

The previous prime is 1999065491. The next prime is 1999065521. The reversal of 1999065501 is 1055609991.

It is a happy number.

1999065501 is a `hidden beast` number, since 1 + 9 + 9 + 90 + 6 + 550 + 1 = 666.

It is not a de Polignac number, because 1999065501 - 2¹⁵ = 1999032733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999065521) 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, 64731 + ... + 90488.

It is an arithmetic number, because the mean of its divisors is an integer number (127125180).

Almost surely, 2^1999065501 is an apocalyptic number.

It is an amenable number.

1999065501 is a deficient number, since it is larger than the sum of its proper divisors (1051938819).

1999065501 is an equidigital number, since it uses as much as digits as its factorization.

1999065501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155287 (or 155275 counting only the distinct ones).

The product of its (nonzero) digits is 109350, while the sum is 45.

The square root of 1999065501 is about 44710.9103128084. The cubic root of 1999065501 is about 1259.7247868302.

It can be divided in two parts, 19990 and 65501, that added together give a triangular number (85491 = T₄₁₃).

The spelling of 1999065501 in words is "one billion, nine hundred ninety-nine million, sixty-five thousand, five hundred one".