321612690 has 64 divisors (see below), whose sum is σ = 890009856. Its totient is φ = 72855552.

The previous prime is 321612689. The next prime is 321612721. The reversal of 321612690 is 96216123.

It is a super-2 number, since 2×321612690² = 206869444738072200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16954 + ... + 30506.

It is an arithmetic number, because the mean of its divisors is an integer number (13906404).

Almost surely, 2^321612690 is an apocalyptic number.

321612690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 321612690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445004928).

321612690 is an abundant number, since it is smaller than the sum of its proper divisors (568397166).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

321612690 is a wasteful number, since it uses less digits than its factorization.

321612690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13683.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 321612690 is about 17933.5632265314. The cubic root of 321612690 is about 685.1374792880.

The spelling of 321612690 in words is "three hundred twenty-one million, six hundred twelve thousand, six hundred ninety".