245617256520 has 192 divisors, whose sum is σ = 806076161280. Its totient is φ = 64857397248.

The previous prime is 245617256471. The next prime is 245617256537. The reversal of 245617256520 is 25652716542.

245617256520 is a `hidden beast` number, since 2 + 4 + 5 + 6 + 1 + 72 + 56 + 520 = 666.

It is a super-2 number, since 2×245617256520² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 57885519 + ... + 57889761.

It is an arithmetic number, because the mean of its divisors is an integer number (4198313340).

Almost surely, 2^245617256520 is an apocalyptic number.

245617256520 is a gapful number since it is divisible by the number (20) 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 245617256520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403038080640).

245617256520 is an abundant number, since it is smaller than the sum of its proper divisors (560458904760).

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

245617256520 is a wasteful number, since it uses less digits than its factorization.

245617256520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5796 (or 5789 counting only the distinct ones).

The product of its (nonzero) digits is 1008000, while the sum is 45.

The spelling of 245617256520 in words is "two hundred forty-five billion, six hundred seventeen million, two hundred fifty-six thousand, five hundred twenty".