21270951 has 16 divisors (see below), whose sum is σ = 33937120. Its totient is φ = 13089600.

The previous prime is 21270947. The next prime is 21270971. The reversal of 21270951 is 15907212.

It is not a de Polignac number, because 21270951 - 2² = 21270947 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21270941) 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 15 ways as a sum of consecutive naturals, for example, 29950 + ... + 30651.

It is an arithmetic number, because the mean of its divisors is an integer number (2121070).

Almost surely, 2^21270951 is an apocalyptic number.

21270951 is a deficient number, since it is larger than the sum of its proper divisors (12666169).

21270951 is a wasteful number, since it uses less digits than its factorization.

21270951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60623 (or 60617 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 21270951 is about 4612.0441238132. The cubic root of 21270951 is about 277.0739114716.

The spelling of 21270951 in words is "twenty-one million, two hundred seventy thousand, nine hundred fifty-one".