321616145 has 4 divisors (see below), whose sum is σ = 385939380. Its totient is φ = 257292912.

The previous prime is 321616121. The next prime is 321616151. The reversal of 321616145 is 541616123.

It is a happy number.

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 132526144 + 189090001 = 11512^2 + 13751^2 .

It is a cyclic number.

It is not a de Polignac number, because 321616145 - 2¹⁸ = 321354001 is a prime.

It is a super-2 number, since 2×321616145² = 206873889449322050, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32161610 + ... + 32161619.

It is an arithmetic number, because the mean of its divisors is an integer number (96484845).

Almost surely, 2^321616145 is an apocalyptic number.

It is an amenable number.

321616145 is a deficient number, since it is larger than the sum of its proper divisors (64323235).

321616145 is an equidigital number, since it uses as much as digits as its factorization.

321616145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64323234.

The product of its digits is 4320, while the sum is 29.

The square root of 321616145 is about 17933.6595540341. The cubic root of 321616145 is about 685.1399326961.

The spelling of 321616145 in words is "three hundred twenty-one million, six hundred sixteen thousand, one hundred forty-five".