21453037 has 2 divisors, whose sum is σ = 21453038. Its totient is φ = 21453036.

The previous prime is 21453017. The next prime is 21453059. The reversal of 21453037 is 73035412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19900521 + 1552516 = 4461^2 + 1246^2 .

It is a cyclic number.

It is not a de Polignac number, because 21453037 - 2⁷ = 21452909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21453017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726518 + 10726519.

It is an arithmetic number, because the mean of its divisors is an integer number (10726519).

Almost surely, 2^21453037 is an apocalyptic number.

It is an amenable number.

21453037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21453037 is an equidigital number, since it uses as much as digits as its factorization.

21453037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21453037 is about 4631.7423287571. The cubic root of 21453037 is about 277.8622793167.

Adding to 21453037 its reverse (73035412), we get a palindrome (94488449).

The spelling of 21453037 in words is "twenty-one million, four hundred fifty-three thousand, thirty-seven".