21046973 has 2 divisors, whose sum is σ = 21046974. Its totient is φ = 21046972.

The previous prime is 21046967. The next prime is 21046979. The reversal of 21046973 is 37964012.

It is a balanced prime because it is at equal distance from previous prime (21046967) and next prime (21046979).

It can be written as a sum of positive squares in only one way, i.e., 19731364 + 1315609 = 4442^2 + 1147^2 .

It is a cyclic number.

It is not a de Polignac number, because 21046973 - 2⁴ = 21046957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21046979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10523486 + 10523487.

It is an arithmetic number, because the mean of its divisors is an integer number (10523487).

Almost surely, 2^21046973 is an apocalyptic number.

It is an amenable number.

21046973 is a deficient number, since it is larger than the sum of its proper divisors (1).

21046973 is an equidigital number, since it uses as much as digits as its factorization.

21046973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 21046973 is about 4587.6980066260. The cubic root of 21046973 is about 276.0979707156.

The spelling of 21046973 in words is "twenty-one million, forty-six thousand, nine hundred seventy-three".