645206142 has 64 divisors (see below), whose sum is σ = 1588561920. Its totient is φ = 170571744.

The previous prime is 645206137. The next prime is 645206167. The reversal of 645206142 is 241602546.

645206142 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent 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, 24913 + ... + 43715.

It is an arithmetic number, because the mean of its divisors is an integer number (24821280).

Almost surely, 2^645206142 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645206142, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (794280960).

645206142 is an abundant number, since it is smaller than the sum of its proper divisors (943355778).

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

645206142 is a wasteful number, since it uses less digits than its factorization.

645206142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18877.

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

The square root of 645206142 is about 25400.9082908466. The cubic root of 645206142 is about 864.1042960730.

Adding to 645206142 its reverse (241602546), we get a palindrome (886808688).

The spelling of 645206142 in words is "six hundred forty-five million, two hundred six thousand, one hundred forty-two".