645867264 has 288 divisors, whose sum is σ = 2147475456. Its totient is φ = 168099840.

The previous prime is 645867259. The next prime is 645867269. The reversal of 645867264 is 462768546.

It is an interprime number because it is at equal distance from previous prime (645867259) and next prime (645867269).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645867269) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3381409 + ... + 3381599.

It is an arithmetic number, because the mean of its divisors is an integer number (7456512).

Almost surely, 2^645867264 is an apocalyptic number.

645867264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645867264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1073737728).

645867264 is an abundant number, since it is smaller than the sum of its proper divisors (1501608192).

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

645867264 is a wasteful number, since it uses less digits than its factorization.

645867264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271 (or 257 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 48.

The square root of 645867264 is about 25413.9187060949. The cubic root of 645867264 is about 864.3993352916.

The spelling of 645867264 in words is "six hundred forty-five million, eight hundred sixty-seven thousand, two hundred sixty-four".