21451012 has 24 divisors (see below), whose sum is σ = 41076000. Its totient is φ = 9720960.

The previous prime is 21451007. The next prime is 21451013. The reversal of 21451012 is 21015412.

It is not an unprimeable number, because it can be changed into a prime (21451013) 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, 21468 + ... + 22444.

It is an arithmetic number, because the mean of its divisors is an integer number (1711500).

Almost surely, 2^21451012 is an apocalyptic number.

21451012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21451012 is a deficient number, since it is larger than the sum of its proper divisors (19624988).

21451012 is a wasteful number, since it uses less digits than its factorization.

21451012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1491 (or 1489 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21451012 is about 4631.5237233550. The cubic root of 21451012 is about 277.8535363616.

Adding to 21451012 its reverse (21015412), we get a palindrome (42466424).

Subtracting from 21451012 its reverse (21015412), we obtain a square (435600 = 660²).

The spelling of 21451012 in words is "twenty-one million, four hundred fifty-one thousand, twelve".