21755031 has 8 divisors (see below), whose sum is σ = 29624064. Its totient is φ = 14194680.

The previous prime is 21755021. The next prime is 21755077. The reversal of 21755031 is 13055712.

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

It is not a de Polignac number, because 21755031 - 2⁹ = 21754519 is a prime.

It is a super-2 number, since 2×21755031² = 946562747621922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21754992 and 21755010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755021) 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, 77005 + ... + 77286.

It is an arithmetic number, because the mean of its divisors is an integer number (3703008).

Almost surely, 2^21755031 is an apocalyptic number.

21755031 is a deficient number, since it is larger than the sum of its proper divisors (7869033).

21755031 is a wasteful number, since it uses less digits than its factorization.

21755031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154341.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 21755031 is about 4664.2288751733. The cubic root of 21755031 is about 279.1600294652.

The spelling of 21755031 in words is "twenty-one million, seven hundred fifty-five thousand, thirty-one".