21451512 has 32 divisors (see below), whose sum is σ = 54046080. Its totient is φ = 7094880.

The previous prime is 21451499. The next prime is 21451519. The reversal of 21451512 is 21515412.

It is a super-2 number, since 2×21451512² = 920334734172288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451519) 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, 268 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (1688940).

Almost surely, 2^21451512 is an apocalyptic number.

It is an amenable number.

21451512 is an abundant number, since it is smaller than the sum of its proper divisors (32594568).

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

21451512 is a wasteful number, since it uses less digits than its factorization.

21451512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6963 (or 6959 counting only the distinct ones).

The product of its digits is 400, while the sum is 21.

The square root of 21451512 is about 4631.5777009568. The cubic root of 21451512 is about 277.8556951671.

Adding to 21451512 its reverse (21515412), we get a palindrome (42966924).

The spelling of 21451512 in words is "twenty-one million, four hundred fifty-one thousand, five hundred twelve".