263642551556640 has 384 divisors, whose sum is σ = 854335218627072. Its totient is φ = 68322612019200.

The previous prime is 263642551556633. The next prime is 263642551556653. The reversal of 263642551556640 is 46655155246362.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 564025102 + ... + 564492338.

It is an arithmetic number, because the mean of its divisors is an integer number (2224831298508).

Almost surely, 2^{263642551556640} is an apocalyptic number.

263642551556640 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 263642551556640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (427167609313536).

263642551556640 is an abundant number, since it is smaller than the sum of its proper divisors (590692667070432).

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

263642551556640 is a wasteful number, since it uses less digits than its factorization.

263642551556640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467572 (or 467564 counting only the distinct ones).

The product of its (nonzero) digits is 155520000, while the sum is 60.

The spelling of 263642551556640 in words is "two hundred sixty-three trillion, six hundred forty-two billion, five hundred fifty-one million, five hundred fifty-six thousand, six hundred forty".