21311602 has 16 divisors (see below), whose sum is σ = 34560792. Its totient is φ = 9797760.

The previous prime is 21311599. The next prime is 21311603. The reversal of 21311602 is 20611312.

21311602 is nontrivially palindromic in base 5.

It can be written as a sum of positive squares in 4 ways, for example, as 20985561 + 326041 = 4581^2 + 571^2 .

It is not an unprimeable number, because it can be changed into a prime (21311603) 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, 5848 + ... + 8764.

Almost surely, 2^21311602 is an apocalyptic number.

21311602 is a deficient number, since it is larger than the sum of its proper divisors (13249190).

21311602 is a wasteful number, since it uses less digits than its factorization.

21311602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3213.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21311602 is about 4616.4490682775. The cubic root of 21311602 is about 277.2503048395.

Adding to 21311602 its reverse (20611312), we get a palindrome (41922914).

The spelling of 21311602 in words is "twenty-one million, three hundred eleven thousand, six hundred two".