21454564 has 6 divisors (see below), whose sum is σ = 37545494. Its totient is φ = 10727280.

The previous prime is 21454547. The next prime is 21454613. The reversal of 21454564 is 46545412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21233664 + 220900 = 4608^2 + 470^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2681817 + ... + 2681824.

Almost surely, 2^21454564 is an apocalyptic number.

It is an amenable number.

21454564 is a deficient number, since it is larger than the sum of its proper divisors (16090930).

21454564 is a wasteful number, since it uses less digits than its factorization.

21454564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5363645 (or 5363643 counting only the distinct ones).

The product of its digits is 19200, while the sum is 31.

The square root of 21454564 is about 4631.9071666000. The cubic root of 21454564 is about 277.8688717887.

Adding to 21454564 its reverse (46545412), we get a palindrome (67999976).

The spelling of 21454564 in words is "twenty-one million, four hundred fifty-four thousand, five hundred sixty-four".