21551453 has 16 divisors (see below), whose sum is σ = 28285440. Its totient is φ = 15908400.

The previous prime is 21551449. The next prime is 21551459. The reversal of 21551453 is 35415512.

It is a cyclic number.

It is not a de Polignac number, because 21551453 - 2² = 21551449 is a prime.

It is a super-2 number, since 2×21551453² = 928930252822418, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5903 + ... + 8828.

It is an arithmetic number, because the mean of its divisors is an integer number (1767840).

Almost surely, 2^21551453 is an apocalyptic number.

It is an amenable number.

21551453 is a deficient number, since it is larger than the sum of its proper divisors (6733987).

21551453 is a wasteful number, since it uses less digits than its factorization.

21551453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14768.

The product of its digits is 3000, while the sum is 26.

The square root of 21551453 is about 4642.3542518856. The cubic root of 21551453 is about 278.2865297933.

Adding to 21551453 its reverse (35415512), we get a palindrome (56966965).

The spelling of 21551453 in words is "twenty-one million, five hundred fifty-one thousand, four hundred fifty-three".