21038737 has 8 divisors (see below), whose sum is σ = 21476576. Its totient is φ = 20604672.

The previous prime is 21038729. The next prime is 21038777. The reversal of 21038737 is 73783012.

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 21038737 - 2³ = 21038729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21038699 and 21038708.

It is not an unprimeable number, because it can be changed into a prime (21038777) 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, 12118 + ... + 13744.

It is an arithmetic number, because the mean of its divisors is an integer number (2684572).

Almost surely, 2^21038737 is an apocalyptic number.

It is an amenable number.

21038737 is a deficient number, since it is larger than the sum of its proper divisors (437839).

21038737 is a wasteful number, since it uses less digits than its factorization.

21038737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1887.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 21038737 is about 4586.8003008633. The cubic root of 21038737 is about 276.0619522414.

The spelling of 21038737 in words is "twenty-one million, thirty-eight thousand, seven hundred thirty-seven".