1620909194 has 4 divisors (see below), whose sum is σ = 2431363794. Its totient is φ = 810454596.

The previous prime is 1620909193. The next prime is 1620909203. The reversal of 1620909194 is 4919090261.

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: 4919090261 = 31 ⋅158680331.

It can be written as a sum of positive squares in only one way, i.e., 1560645025 + 60264169 = 39505^2 + 7763^2 .

It is not an unprimeable number, because it can be changed into a prime (1620909193) 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 as a sum of consecutive naturals, namely, 405227297 + ... + 405227300.

Almost surely, 2^1620909194 is an apocalyptic number.

1620909194 is a deficient number, since it is larger than the sum of its proper divisors (810454600).

1620909194 is an equidigital number, since it uses as much as digits as its factorization.

1620909194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810454599.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 1620909194 is about 40260.5165639985. The cubic root of 1620909194 is about 1174.6799657149.

The spelling of 1620909194 in words is "one billion, six hundred twenty million, nine hundred nine thousand, one hundred ninety-four".