1621309233 has 4 divisors (see below), whose sum is σ = 2161745648. Its totient is φ = 1080872820.

The previous prime is 1621309231. The next prime is 1621309247. The reversal of 1621309233 is 3329031261.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3329031261 = 3 ⋅1109677087.

It is not a de Polignac number, because 1621309233 - 2¹ = 1621309231 is a prime.

It is a super-2 number, since 2×1621309233² = 5257287258022096578, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621309233.

It is not an unprimeable number, because it can be changed into a prime (1621309231) 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, 270218203 + ... + 270218208.

It is an arithmetic number, because the mean of its divisors is an integer number (540436412).

Almost surely, 2^1621309233 is an apocalyptic number.

It is an amenable number.

1621309233 is a deficient number, since it is larger than the sum of its proper divisors (540436415).

1621309233 is an equidigital number, since it uses as much as digits as its factorization.

1621309233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540436414.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 1621309233 is about 40265.4843879966. The cubic root of 1621309233 is about 1174.7765944357.

The spelling of 1621309233 in words is "one billion, six hundred twenty-one million, three hundred nine thousand, two hundred thirty-three".