21150031 has 8 divisors (see below), whose sum is σ = 24306464. Its totient is φ = 18027360.

The previous prime is 21150011. The next prime is 21150037. The reversal of 21150031 is 13005112.

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

It is a cyclic number.

It is not a de Polignac number, because 21150031 - 2¹⁵ = 21117263 is a prime.

It is a super-2 number, since 2×21150031² = 894647622601922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21149993 and 21150020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7080 + ... + 9613.

It is an arithmetic number, because the mean of its divisors is an integer number (3038308).

Almost surely, 2^21150031 is an apocalyptic number.

21150031 is a deficient number, since it is larger than the sum of its proper divisors (3156433).

21150031 is a wasteful number, since it uses less digits than its factorization.

21150031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16881.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21150031 is about 4598.9162853872. The cubic root of 21150031 is about 276.5478816217.

Adding to 21150031 its reverse (13005112), we get a palindrome (34155143).

The spelling of 21150031 in words is "twenty-one million, one hundred fifty thousand, thirty-one".