21057467 has 2 divisors, whose sum is σ = 21057468. Its totient is φ = 21057466.

The previous prime is 21057433. The next prime is 21057479. The reversal of 21057467 is 76475012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21057467 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21057427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10528733 + 10528734.

It is an arithmetic number, because the mean of its divisors is an integer number (10528734).

Almost surely, 2^21057467 is an apocalyptic number.

21057467 is a deficient number, since it is larger than the sum of its proper divisors (1).

21057467 is an equidigital number, since it uses as much as digits as its factorization.

21057467 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21057467 is about 4588.8415749511. The cubic root of 21057467 is about 276.1438504833.

The spelling of 21057467 in words is "twenty-one million, fifty-seven thousand, four hundred sixty-seven".