21101264 has 10 divisors (see below), whose sum is σ = 40883730. Its totient is φ = 10550624.

The previous prime is 21101263. The next prime is 21101273. The reversal of 21101264 is 46210112.

It can be written as a sum of positive squares in only one way, i.e., 15147664 + 5953600 = 3892^2 + 2440^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 659399 + ... + 659430.

It is an arithmetic number, because the mean of its divisors is an integer number (4088373).

Almost surely, 2^21101264 is an apocalyptic number.

It is an amenable number.

21101264 is a deficient number, since it is larger than the sum of its proper divisors (19782466).

21101264 is a wasteful number, since it uses less digits than its factorization.

21101264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1318837 (or 1318831 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21101264 is about 4593.6112155906. The cubic root of 21101264 is about 276.3351665775.

Adding to 21101264 its reverse (46210112), we get a palindrome (67311376).

The spelling of 21101264 in words is "twenty-one million, one hundred one thousand, two hundred sixty-four".