645668496 has 240 divisors, whose sum is σ = 2114531328. Its totient is φ = 188956800.

The previous prime is 645668479. The next prime is 645668503. The reversal of 645668496 is 694866546.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1325565 + ... + 1326051.

Almost surely, 2^645668496 is an apocalyptic number.

645668496 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

645668496 is the 16071-st heptagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645668496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1057265664).

645668496 is an abundant number, since it is smaller than the sum of its proper divisors (1468862832).

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

645668496 is a wasteful number, since it uses less digits than its factorization.

645668496 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552 (or 534 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 54.

The square root of 645668496 is about 25410.0077922066. The cubic root of 645668496 is about 864.3106521802.

The spelling of 645668496 in words is "six hundred forty-five million, six hundred sixty-eight thousand, four hundred ninety-six".