21954403 has 2 divisors, whose sum is σ = 21954404. Its totient is φ = 21954402.

The previous prime is 21954391. The next prime is 21954461. The reversal of 21954403 is 30445912.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21954403 is a prime.

It is a super-2 number, since 2×21954403² = 963991622172818, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21954103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10977201 + 10977202.

It is an arithmetic number, because the mean of its divisors is an integer number (10977202).

Almost surely, 2^21954403 is an apocalyptic number.

21954403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21954403 is an equidigital number, since it uses as much as digits as its factorization.

21954403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 21954403 is about 4685.5525821401. The cubic root of 21954403 is about 280.0102164640.

The spelling of 21954403 in words is "twenty-one million, nine hundred fifty-four thousand, four hundred three".