21310461 has 6 divisors (see below), whose sum is σ = 30781790. Its totient is φ = 14206968.

The previous prime is 21310459. The next prime is 21310477. The reversal of 21310461 is 16401312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20985561 + 324900 = 4581^2 + 570^2 .

It is not a de Polignac number, because 21310461 - 2¹ = 21310459 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 (21310451) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1183906 + ... + 1183923.

Almost surely, 2^21310461 is an apocalyptic number.

It is an amenable number.

21310461 is a deficient number, since it is larger than the sum of its proper divisors (9471329).

21310461 is a wasteful number, since it uses less digits than its factorization.

21310461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2367835 (or 2367832 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21310461 is about 4616.3254867914. The cubic root of 21310461 is about 277.2453568579.

Adding to 21310461 its reverse (16401312), we get a palindrome (37711773).

The spelling of 21310461 in words is "twenty-one million, three hundred ten thousand, four hundred sixty-one".