21342737 has 8 divisors (see below), whose sum is σ = 23133096. Its totient is φ = 19573632.

The previous prime is 21342721. The next prime is 21342773. The reversal of 21342737 is 73724312.

It can be written as a sum of positive squares in 4 ways, for example, as 2193361 + 19149376 = 1481^2 + 4376^2 .

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

It is not a de Polignac number, because 21342737 - 2⁴ = 21342721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21342337) 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, 3188 + ... + 7269.

It is an arithmetic number, because the mean of its divisors is an integer number (2891637).

Almost surely, 2^21342737 is an apocalyptic number.

It is an amenable number.

21342737 is a deficient number, since it is larger than the sum of its proper divisors (1790359).

21342737 is a wasteful number, since it uses less digits than its factorization.

21342737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10627.

The product of its digits is 7056, while the sum is 29.

The square root of 21342737 is about 4619.8200181392. The cubic root of 21342737 is about 277.3852546185.

The spelling of 21342737 in words is "twenty-one million, three hundred forty-two thousand, seven hundred thirty-seven".