21573371 has 2 divisors, whose sum is σ = 21573372. Its totient is φ = 21573370.

The previous prime is 21573367. The next prime is 21573407. The reversal of 21573371 is 17337512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21573371 - 2² = 21573367 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21573301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10786685 + 10786686.

It is an arithmetic number, because the mean of its divisors is an integer number (10786686).

Almost surely, 2^21573371 is an apocalyptic number.

21573371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21573371 is an equidigital number, since it uses as much as digits as its factorization.

21573371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4410, while the sum is 29.

The square root of 21573371 is about 4644.7143076835. The cubic root of 21573371 is about 278.3808377051.

The spelling of 21573371 in words is "twenty-one million, five hundred seventy-three thousand, three hundred seventy-one".