645662620 has 12 divisors (see below), whose sum is σ = 1355891544. Its totient is φ = 258265040.

The previous prime is 645662609. The next prime is 645662621. The reversal of 645662620 is 26266546.

It is a happy number.

645662620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 645662620.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645662621) 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, 16141546 + ... + 16141585.

It is an arithmetic number, because the mean of its divisors is an integer number (112990962).

Almost surely, 2^645662620 is an apocalyptic number.

It is an amenable number.

645662620 is an abundant number, since it is smaller than the sum of its proper divisors (710228924).

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

645662620 is a wasteful number, since it uses less digits than its factorization.

645662620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32283140 (or 32283138 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 37.

The square root of 645662620 is about 25409.8921682088. The cubic root of 645662620 is about 864.3080302440.

The spelling of 645662620 in words is "six hundred forty-five million, six hundred sixty-two thousand, six hundred twenty".