645379280 has 80 divisors (see below), whose sum is σ = 1846798464. Its totient is φ = 204249600.

The previous prime is 645379277. The next prime is 645379283. The reversal of 645379280 is 82973546.

It is an interprime number because it is at equal distance from previous prime (645379277) and next prime (645379283).

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645379283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37046 + ... + 51605.

Almost surely, 2^645379280 is an apocalyptic number.

It is an amenable number.

645379280 is an abundant number, since it is smaller than the sum of its proper divisors (1201419184).

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

645379280 is a wasteful number, since it uses less digits than its factorization.

645379280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88684 (or 88678 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 44.

The square root of 645379280 is about 25404.3161687143. The cubic root of 645379280 is about 864.1815819199.

The spelling of 645379280 in words is "six hundred forty-five million, three hundred seventy-nine thousand, two hundred eighty".