21996155 has 8 divisors (see below), whose sum is σ = 26767584. Its totient is φ = 17348800.

The previous prime is 21996151. The next prime is 21996157. The reversal of 21996155 is 55169912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21996155 - 2² = 21996151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21996151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30626 + ... + 31335.

It is an arithmetic number, because the mean of its divisors is an integer number (3345948).

Almost surely, 2^21996155 is an apocalyptic number.

21996155 is a deficient number, since it is larger than the sum of its proper divisors (4771429).

21996155 is an equidigital number, since it uses as much as digits as its factorization.

21996155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62037.

The product of its digits is 24300, while the sum is 38.

The square root of 21996155 is about 4690.0058635358. The cubic root of 21996155 is about 280.1876081126.

The spelling of 21996155 in words is "twenty-one million, nine hundred ninety-six thousand, one hundred fifty-five".