21276151 has 4 divisors (see below), whose sum is σ = 22912792. Its totient is φ = 19639512.

The previous prime is 21276149. The next prime is 21276179. The reversal of 21276151 is 15167212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21276151 - 2¹ = 21276149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21276121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 818301 + ... + 818326.

It is an arithmetic number, because the mean of its divisors is an integer number (5728198).

Almost surely, 2^21276151 is an apocalyptic number.

21276151 is a deficient number, since it is larger than the sum of its proper divisors (1636641).

21276151 is a wasteful number, since it uses less digits than its factorization.

21276151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636640.

The product of its digits is 840, while the sum is 25.

The square root of 21276151 is about 4612.6078307179. The cubic root of 21276151 is about 277.0964879101.

It can be divided in two parts, 212761 and 51, that multiplied together give a triangular number (10850811 = T₄₆₅₈).

The spelling of 21276151 in words is "twenty-one million, two hundred seventy-six thousand, one hundred fifty-one".