387322991 has 4 divisors (see below), whose sum is σ = 422534184. Its totient is φ = 352111800.

The previous prime is 387322939. The next prime is 387323009. The reversal of 387322991 is 199223783.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-387322991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387372991) 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, 17605580 + ... + 17605601.

It is an arithmetic number, because the mean of its divisors is an integer number (105633546).

Almost surely, 2^387322991 is an apocalyptic number.

387322991 is a deficient number, since it is larger than the sum of its proper divisors (35211193).

387322991 is a wasteful number, since it uses less digits than its factorization.

387322991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35211192.

The product of its digits is 163296, while the sum is 44.

The square root of 387322991 is about 19680.5231383721. The cubic root of 387322991 is about 728.9388416401.

The spelling of 387322991 in words is "three hundred eighty-seven million, three hundred twenty-two thousand, nine hundred ninety-one".