21454729650 has 72 divisors (see below), whose sum is σ = 57900460800. Its totient is φ = 5695578720.

The previous prime is 21454729601. The next prime is 21454729651. The reversal of 21454729650 is 5692745412.

21454729650 is a `hidden beast` number, since 2 + 1 + 45 + 472 + 96 + 50 = 666.

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

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21454729596 and 21454729605.

It is not an unprimeable number, because it can be changed into a prime (21454729651) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6550 + ... + 207249.

Almost surely, 2^21454729650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21454729650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28950230400).

21454729650 is an abundant number, since it is smaller than the sum of its proper divisors (36445731150).

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

21454729650 is a wasteful number, since it uses less digits than its factorization.

21454729650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214040 (or 214032 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 21454729650 in words is "twenty-one billion, four hundred fifty-four million, seven hundred twenty-nine thousand, six hundred fifty".