21750629 has 2 divisors, whose sum is σ = 21750630. Its totient is φ = 21750628.

The previous prime is 21750563. The next prime is 21750661. The reversal of 21750629 is 92605712.

It is an a-pointer prime, because the next prime (21750661) can be obtained adding 21750629 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12888100 + 8862529 = 3590^2 + 2977^2 .

It is a cyclic number.

It is not a de Polignac number, because 21750629 - 2⁸ = 21750373 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21750595 and 21750604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21750689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10875314 + 10875315.

It is an arithmetic number, because the mean of its divisors is an integer number (10875315).

Almost surely, 2^21750629 is an apocalyptic number.

It is an amenable number.

21750629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21750629 is an equidigital number, since it uses as much as digits as its factorization.

21750629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 21750629 is about 4663.7569619353. The cubic root of 21750629 is about 279.1411994094.

The spelling of 21750629 in words is "twenty-one million, seven hundred fifty thousand, six hundred twenty-nine".