1620213161 has 4 divisors (see below), whose sum is σ = 1851672192. Its totient is φ = 1388754132.

The previous prime is 1620213157. The next prime is 1620213193. The reversal of 1620213161 is 1613120261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1620213161 - 2² = 1620213157 is a prime.

It is a super-2 number, since 2×1620213161² = 5250181374155223842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620218161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115729505 + ... + 115729518.

It is an arithmetic number, because the mean of its divisors is an integer number (462918048).

Almost surely, 2^1620213161 is an apocalyptic number.

It is an amenable number.

1620213161 is a deficient number, since it is larger than the sum of its proper divisors (231459031).

1620213161 is an equidigital number, since it uses as much as digits as its factorization.

1620213161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231459030.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1620213161 is about 40251.8715217069. The cubic root of 1620213161 is about 1174.5118022582.

The spelling of 1620213161 in words is "one billion, six hundred twenty million, two hundred thirteen thousand, one hundred sixty-one".