321991402 has 4 divisors (see below), whose sum is σ = 482987106. Its totient is φ = 160995700.

The previous prime is 321991399. The next prime is 321991517. The reversal of 321991402 is 204199123.

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

It can be written as a sum of positive squares in only one way, i.e., 246144721 + 75846681 = 15689^2 + 8709^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80497849 + ... + 80497852.

Almost surely, 2^321991402 is an apocalyptic number.

321991402 is a deficient number, since it is larger than the sum of its proper divisors (160995704).

321991402 is a wasteful number, since it uses less digits than its factorization.

321991402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160995703.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 321991402 is about 17944.1188694235. The cubic root of 321991402 is about 685.4062995329.

The spelling of 321991402 in words is "three hundred twenty-one million, nine hundred ninety-one thousand, four hundred two".