21470537 has 4 divisors (see below), whose sum is σ = 23422416. Its totient is φ = 19518660.

The previous prime is 21470521. The next prime is 21470543. The reversal of 21470537 is 73507412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21470537 - 2⁴ = 21470521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21470557) 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 3 ways as a sum of consecutive naturals, for example, 975923 + ... + 975944.

It is an arithmetic number, because the mean of its divisors is an integer number (5855604).

Almost surely, 2^21470537 is an apocalyptic number.

It is an amenable number.

21470537 is a deficient number, since it is larger than the sum of its proper divisors (1951879).

21470537 is a wasteful number, since it uses less digits than its factorization.

21470537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1951878.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 21470537 is about 4633.6310815601. The cubic root of 21470537 is about 277.9378128071.

Adding to 21470537 its reverse (73507412), we get a palindrome (94977949).

The spelling of 21470537 in words is "twenty-one million, four hundred seventy thousand, five hundred thirty-seven".