21053983 has 2 divisors, whose sum is σ = 21053984. Its totient is φ = 21053982.

The previous prime is 21053969. The next prime is 21053987. The reversal of 21053983 is 38935012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21053983 - 2¹⁷ = 20922911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21053987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10526991 + 10526992.

It is an arithmetic number, because the mean of its divisors is an integer number (10526992).

Almost surely, 2^21053983 is an apocalyptic number.

21053983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21053983 is an equidigital number, since it uses as much as digits as its factorization.

21053983 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21053983 is about 4588.4619427429. The cubic root of 21053983 is about 276.1286201260.

Adding to 21053983 its reverse (38935012), we get a palindrome (59988995).

It can be divided in two parts, 2105398 and 3, that added together give a square (2105401 = 1451²).

The spelling of 21053983 in words is "twenty-one million, fifty-three thousand, nine hundred eighty-three".