21049554240 has 784 divisors, whose sum is σ = 88430380416. Its totient is φ = 4702924800.

The previous prime is 21049554209. The next prime is 21049554257. The reversal of 21049554240 is 4245594012.

It is a happy number.

21049554240 is a `hidden beast` number, since 2 + 104 + 9 + 5 + 542 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21049554195 and 21049554204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 33358725 + ... + 33359355.

Almost surely, 2^21049554240 is an apocalyptic number.

21049554240 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 21049554240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44215190208).

21049554240 is an abundant number, since it is smaller than the sum of its proper divisors (67380826176).

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

21049554240 is a wasteful number, since it uses less digits than its factorization.

21049554240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690 (or 665 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 21049554240 in words is "twenty-one billion, forty-nine million, five hundred fifty-four thousand, two hundred forty".