21451722 has 32 divisors (see below), whose sum is σ = 47822400. Its totient is φ = 6375168.

The previous prime is 21451673. The next prime is 21451723. The reversal of 21451722 is 22715412.

It is a junction number, because it is equal to n+sod(n) for n = 21451692 and 21451701.

It is not an unprimeable number, because it can be changed into a prime (21451723) 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 15 ways as a sum of consecutive naturals, for example, 3597 + ... + 7472.

It is an arithmetic number, because the mean of its divisors is an integer number (1494450).

Almost surely, 2^21451722 is an apocalyptic number.

21451722 is an abundant number, since it is smaller than the sum of its proper divisors (26370678).

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

21451722 is a wasteful number, since it uses less digits than its factorization.

21451722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11110.

The product of its digits is 1120, while the sum is 24.

The square root of 21451722 is about 4631.6003713619. The cubic root of 21451722 is about 277.8566018554.

The spelling of 21451722 in words is "twenty-one million, four hundred fifty-one thousand, seven hundred twenty-two".