21253235056240 has 40 divisors (see below), whose sum is σ = 53905932553968. Its totient is φ = 7728449111040.

The previous prime is 21253235056187. The next prime is 21253235056247. The reversal of 21253235056240 is 4265053235212.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 21253235056193 and 21253235056202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253235056247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12075700857 + ... + 12075702616.

Almost surely, 2^{21253235056240} is an apocalyptic number.

21253235056240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21253235056240 is an abundant number, since it is smaller than the sum of its proper divisors (32652697497728).

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

21253235056240 is a wasteful number, since it uses less digits than its factorization.

21253235056240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24151403497 (or 24151403491 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 40.

The spelling of 21253235056240 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred thirty-five million, fifty-six thousand, two hundred forty".