645311442 has 16 divisors (see below), whose sum is σ = 1295219232. Its totient is φ = 214337760.

The previous prime is 645311417. The next prime is 645311461. The reversal of 645311442 is 244113546.

It is a super-2 number, since 2×645311442² = 832853714352238728, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189688 + ... + 193059.

It is an arithmetic number, because the mean of its divisors is an integer number (80951202).

Almost surely, 2^645311442 is an apocalyptic number.

645311442 is an abundant number, since it is smaller than the sum of its proper divisors (649907790).

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

645311442 is a wasteful number, since it uses less digits than its factorization.

645311442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383033.

The product of its digits is 11520, while the sum is 30.

The square root of 645311442 is about 25402.9809668078. The cubic root of 645311442 is about 864.1513018421.

Adding to 645311442 its reverse (244113546), we get a palindrome (889424988).

The spelling of 645311442 in words is "six hundred forty-five million, three hundred eleven thousand, four hundred forty-two".