21347955 has 20 divisors (see below), whose sum is σ = 38268912. Its totient is φ = 11385360.

The previous prime is 21347951. The next prime is 21347957. The reversal of 21347955 is 55974312.

It is not a de Polignac number, because 21347955 - 2² = 21347951 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21347951) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 25951 + ... + 26760.

Almost surely, 2^21347955 is an apocalyptic number.

21347955 is a deficient number, since it is larger than the sum of its proper divisors (16920957).

21347955 is an equidigital number, since it uses as much as digits as its factorization.

21347955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52728 (or 52719 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 21347955 is about 4620.3847242410. The cubic root of 21347955 is about 277.4078583786.

The spelling of 21347955 in words is "twenty-one million, three hundred forty-seven thousand, nine hundred fifty-five".