21489131 has 8 divisors (see below), whose sum is σ = 21809520. Its totient is φ = 21171168.

The previous prime is 21489101. The next prime is 21489137. The reversal of 21489131 is 13198412.

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 21489131 - 2¹⁴ = 21472747 is a prime.

It is a super-2 number, since 2×21489131² = 923565502270322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21489094 and 21489103.

It is not an unprimeable number, because it can be changed into a prime (21489137) 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, 24065 + ... + 24941.

It is an arithmetic number, because the mean of its divisors is an integer number (2726190).

Almost surely, 2^21489131 is an apocalyptic number.

21489131 is a deficient number, since it is larger than the sum of its proper divisors (320389).

21489131 is a wasteful number, since it uses less digits than its factorization.

21489131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1213.

The product of its digits is 1728, while the sum is 29.

The square root of 21489131 is about 4635.6370651724. The cubic root of 21489131 is about 278.0180232609.

The spelling of 21489131 in words is "twenty-one million, four hundred eighty-nine thousand, one hundred thirty-one".