21945513450 has 48 divisors (see below), whose sum is σ = 62199858240. Its totient is φ = 5016117120.

The previous prime is 21945513431. The next prime is 21945513481. The reversal of 21945513450 is 5431554912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21945513399 and 21945513408.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10449195 + ... + 10451294.

It is an arithmetic number, because the mean of its divisors is an integer number (1295830380).

Almost surely, 2^21945513450 is an apocalyptic number.

21945513450 is an abundant number, since it is smaller than the sum of its proper divisors (40254344790).

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

21945513450 is a wasteful number, since it uses less digits than its factorization.

21945513450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20900511 (or 20900506 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 39.

The spelling of 21945513450 in words is "twenty-one billion, nine hundred forty-five million, five hundred thirteen thousand, four hundred fifty".