1621066633 has 4 divisors (see below), whose sum is σ = 1636805248. Its totient is φ = 1605328020.

The previous prime is 1621066591. The next prime is 1621066661. The reversal of 1621066633 is 3366601261.

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 1621066633 - 2²¹ = 1618969481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621036633) 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, 7869153 + ... + 7869358.

It is an arithmetic number, because the mean of its divisors is an integer number (409201312).

Almost surely, 2^1621066633 is an apocalyptic number.

It is an amenable number.

1621066633 is a deficient number, since it is larger than the sum of its proper divisors (15738615).

1621066633 is a wasteful number, since it uses less digits than its factorization.

1621066633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15738614.

The product of its (nonzero) digits is 23328, while the sum is 34.

The square root of 1621066633 is about 40262.4717696269. The cubic root of 1621066633 is about 1174.7179967270.

Adding to 1621066633 its reverse (3366601261), we get a palindrome (4987667894).

The spelling of 1621066633 in words is "one billion, six hundred twenty-one million, sixty-six thousand, six hundred thirty-three".