645943534 has 4 divisors (see below), whose sum is σ = 968915304. Its totient is φ = 322971766.

The previous prime is 645943531. The next prime is 645943547. The reversal of 645943534 is 435349546.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645943531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161485882 + ... + 161485885.

It is an arithmetic number, because the mean of its divisors is an integer number (242228826).

Almost surely, 2^645943534 is an apocalyptic number.

645943534 is a deficient number, since it is larger than the sum of its proper divisors (322971770).

645943534 is a wasteful number, since it uses less digits than its factorization.

645943534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322971769.

The product of its digits is 777600, while the sum is 43.

The square root of 645943534 is about 25415.4192174750. The cubic root of 645943534 is about 864.4333593840.

The spelling of 645943534 in words is "six hundred forty-five million, nine hundred forty-three thousand, five hundred thirty-four".