21387141 has 24 divisors (see below), whose sum is σ = 32745440. Its totient is φ = 13413600.

The previous prime is 21387109. The next prime is 21387151. The reversal of 21387141 is 14178312.

It is not a de Polignac number, because 21387141 - 2⁵ = 21387109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30606 + ... + 31296.

Almost surely, 2^21387141 is an apocalyptic number.

It is an amenable number.

21387141 is a deficient number, since it is larger than the sum of its proper divisors (11358299).

21387141 is a wasteful number, since it uses less digits than its factorization.

21387141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897 (or 894 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 21387141 is about 4624.6233360134. The cubic root of 21387141 is about 277.5774899251.

It can be divided in two parts, 21387 and 141, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 21387141 in words is "twenty-one million, three hundred eighty-seven thousand, one hundred forty-one".