21270651 has 8 divisors (see below), whose sum is σ = 28469760. Its totient is φ = 14125992.

The previous prime is 21270643. The next prime is 21270673. The reversal of 21270651 is 15607212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21270651 - 2³ = 21270643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21270551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12691 + ... + 14268.

It is an arithmetic number, because the mean of its divisors is an integer number (3558720).

Almost surely, 2^21270651 is an apocalyptic number.

21270651 is a deficient number, since it is larger than the sum of its proper divisors (7199109).

21270651 is a wasteful number, since it uses less digits than its factorization.

21270651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27225.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21270651 is about 4612.0116001589. The cubic root of 21270651 is about 277.0726088725.

Adding to 21270651 its reverse (15607212), we get a palindrome (36877863).

The spelling of 21270651 in words is "twenty-one million, two hundred seventy thousand, six hundred fifty-one".