21037955 has 4 divisors (see below), whose sum is σ = 25245552. Its totient is φ = 16830360.

The previous prime is 21037949. The next prime is 21037957. The reversal of 21037955 is 55973012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21037955 - 2⁸ = 21037699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21037957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2103791 + ... + 2103800.

It is an arithmetic number, because the mean of its divisors is an integer number (6311388).

Almost surely, 2^21037955 is an apocalyptic number.

21037955 is a deficient number, since it is larger than the sum of its proper divisors (4207597).

21037955 is an equidigital number, since it uses as much as digits as its factorization.

21037955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4207596.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 21037955 is about 4586.7150554618. The cubic root of 21037955 is about 276.0585318346.

The spelling of 21037955 in words is "twenty-one million, thirty-seven thousand, nine hundred fifty-five".