21451670 has 16 divisors (see below), whose sum is σ = 39048480. Its totient is φ = 8483904.

The previous prime is 21451669. The next prime is 21451673. The reversal of 21451670 is 7615412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451673) 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, 11162 + ... + 12941.

It is an arithmetic number, because the mean of its divisors is an integer number (2440530).

Almost surely, 2^21451670 is an apocalyptic number.

21451670 is a deficient number, since it is larger than the sum of its proper divisors (17596810).

21451670 is a wasteful number, since it uses less digits than its factorization.

21451670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24199.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 21451670 is about 4631.5947577481. The cubic root of 21451670 is about 277.8563773427.

The spelling of 21451670 in words is "twenty-one million, four hundred fifty-one thousand, six hundred seventy".