2391390 has 64 divisors (see below), whose sum is σ = 6765120. Its totient is φ = 599040.

The previous prime is 2391349. The next prime is 2391401. The reversal of 2391390 is 931932.

2391390 = 153² + 154² + ... + 220².

It is a super-2 number, since 2×2391390² = 11437492264200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 9.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4330 + ... + 4850.

It is an arithmetic number, because the mean of its divisors is an integer number (105705).

2^2391390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2391390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3382560).

2391390 is an abundant number, since it is smaller than the sum of its proper divisors (4373730).

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

2391390 is a wasteful number, since it uses less digits than its factorization.

2391390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 2391390 is about 1546.4119761564. The cubic root of 2391390 is about 133.7262921266.

The spelling of 2391390 in words is "two million, three hundred ninety-one thousand, three hundred ninety".