21145445450 has 24 divisors (see below), whose sum is σ = 39345091500. Its totient is φ = 8455046400.

The previous prime is 21145445441. The next prime is 21145445471. The reversal of 21145445450 is 5454454112.

It can be written as a sum of positive squares in 6 ways, for example, as 1534523929 + 19610921521 = 39173^2 + 140039^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21145445450.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60530 + ... + 214370.

Almost surely, 2^21145445450 is an apocalyptic number.

21145445450 is a deficient number, since it is larger than the sum of its proper divisors (18199646050).

21145445450 is a wasteful number, since it uses less digits than its factorization.

21145445450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156602 (or 156597 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 35.

Adding to 21145445450 its reverse (5454454112), we get a palindrome (26599899562).

The spelling of 21145445450 in words is "twenty-one billion, one hundred forty-five million, four hundred forty-five thousand, four hundred fifty".