1299949920 has 144 divisors (see below), whose sum is σ = 4453459920. Its totient is φ = 345295872.

The previous prime is 1299949883. The next prime is 1299949943. The reversal of 1299949920 is 299499921.

1299949920 is a `hidden beast` number, since 129 + 9 + 9 + 499 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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, 397251 + ... + 400509.

It is an arithmetic number, because the mean of its divisors is an integer number (30926805).

Almost surely, 2^1299949920 is an apocalyptic number.

1299949920 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 1299949920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2226729960).

1299949920 is an abundant number, since it is smaller than the sum of its proper divisors (3153510000).

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

1299949920 is a wasteful number, since it uses less digits than its factorization.

1299949920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3557 (or 3546 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 54.

The square root of 1299949920 is about 36054.8182633057. The cubic root of 1299949920 is about 1091.3788682771.

The spelling of 1299949920 in words is "one billion, two hundred ninety-nine million, nine hundred forty-nine thousand, nine hundred twenty".