21001802356560 has 160 divisors (see below), whose sum is σ = 65714539714560. Its totient is φ = 5548115865600.

The previous prime is 21001802356537. The next prime is 21001802356637. The reversal of 21001802356560 is 6565320810012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153778705 + ... + 153915215.

It is an arithmetic number, because the mean of its divisors is an integer number (410715873216).

Almost surely, 2^{21001802356560} is an apocalyptic number.

21001802356560 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 21001802356560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32857269857280).

21001802356560 is an abundant number, since it is smaller than the sum of its proper divisors (44712737358000).

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

21001802356560 is a wasteful number, since it uses less digits than its factorization.

21001802356560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142517 (or 142511 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The spelling of 21001802356560 in words is "twenty-one trillion, one billion, eight hundred two million, three hundred fifty-six thousand, five hundred sixty".