1621220329 has 4 divisors (see below), whose sum is σ = 1636094020. Its totient is φ = 1606346640.

The previous prime is 1621220327. The next prime is 1621220347. The reversal of 1621220329 is 9230221261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 981130329 + 640090000 = 31323^2 + 25300^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621220329 - 2¹ = 1621220327 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1621220297 and 1621220306.

It is not an unprimeable number, because it can be changed into a prime (1621220327) 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, 7436682 + ... + 7436899.

It is an arithmetic number, because the mean of its divisors is an integer number (409023505).

Almost surely, 2^1621220329 is an apocalyptic number.

It is an amenable number.

1621220329 is a deficient number, since it is larger than the sum of its proper divisors (14873691).

1621220329 is a wasteful number, since it uses less digits than its factorization.

1621220329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14873690.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 1621220329 is about 40264.3804000509. The cubic root of 1621220329 is about 1174.7551212038.

The spelling of 1621220329 in words is "one billion, six hundred twenty-one million, two hundred twenty thousand, three hundred twenty-nine".