1620707899 has 4 divisors (see below), whose sum is σ = 1624670920. Its totient is φ = 1616744880.

The previous prime is 1620707897. The next prime is 1620707917. The reversal of 1620707899 is 9987070261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9987070261 = 7 ⋅1426724323.

It is a cyclic number.

It is not a de Polignac number, because 1620707899 - 2¹ = 1620707897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620707897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1980897 + ... + 1981714.

It is an arithmetic number, because the mean of its divisors is an integer number (406167730).

Almost surely, 2^1620707899 is an apocalyptic number.

1620707899 is a deficient number, since it is larger than the sum of its proper divisors (3963021).

1620707899 is an equidigital number, since it uses as much as digits as its factorization.

1620707899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3963020.

The product of its (nonzero) digits is 381024, while the sum is 49.

The square root of 1620707899 is about 40258.0165805520. The cubic root of 1620707899 is about 1174.6313372469.

The spelling of 1620707899 in words is "one billion, six hundred twenty million, seven hundred seven thousand, eight hundred ninety-nine".