21361747 has 8 divisors (see below), whose sum is σ = 23378112. Its totient is φ = 19357800.

The previous prime is 21361729. The next prime is 21361763. The reversal of 21361747 is 74716312.

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

It is not a de Polignac number, because 21361747 - 2⁷ = 21361619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21361727) 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 7 ways as a sum of consecutive naturals, for example, 708 + ... + 6574.

It is an arithmetic number, because the mean of its divisors is an integer number (2922264).

Almost surely, 2^21361747 is an apocalyptic number.

21361747 is a deficient number, since it is larger than the sum of its proper divisors (2016365).

21361747 is a wasteful number, since it uses less digits than its factorization.

21361747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6209.

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

The square root of 21361747 is about 4621.8769996615. The cubic root of 21361747 is about 277.4675859659.

It can be divided in two parts, 2136 and 1747, that added together give a palindrome (3883).

The spelling of 21361747 in words is "twenty-one million, three hundred sixty-one thousand, seven hundred forty-seven".