21051464 has 32 divisors (see below), whose sum is σ = 45299520. Its totient is φ = 8984256.

The previous prime is 21051461. The next prime is 21051473. The reversal of 21051464 is 46415012.

It is not an unprimeable number, because it can be changed into a prime (21051461) 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, 15767 + ... + 17049.

It is an arithmetic number, because the mean of its divisors is an integer number (1415610).

Almost surely, 2^21051464 is an apocalyptic number.

It is an amenable number.

21051464 is an abundant number, since it is smaller than the sum of its proper divisors (24248056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21051464 is a wasteful number, since it uses less digits than its factorization.

21051464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589 (or 1585 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21051464 is about 4588.1874416811. The cubic root of 21051464 is about 276.1176072338.

Adding to 21051464 its reverse (46415012), we get a palindrome (67466476).

The spelling of 21051464 in words is "twenty-one million, fifty-one thousand, four hundred sixty-four".