645123720070 has 8 divisors (see below), whose sum is σ = 1161222696144. Its totient is φ = 258049488024.

The previous prime is 645123719983. The next prime is 645123720071. The reversal of 645123720070 is 70027321546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×645123720070² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645123720071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32256185994 + ... + 32256186013.

It is an arithmetic number, because the mean of its divisors is an integer number (145152837018).

Almost surely, 2^645123720070 is an apocalyptic number.

645123720070 is a deficient number, since it is larger than the sum of its proper divisors (516098976074).

645123720070 is a wasteful number, since it uses less digits than its factorization.

645123720070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64512372014.

The product of its (nonzero) digits is 70560, while the sum is 37.

The spelling of 645123720070 in words is "six hundred forty-five billion, one hundred twenty-three million, seven hundred twenty thousand, seventy".