21965151 has 16 divisors (see below), whose sum is σ = 32628960. Its totient is φ = 13050240.

The previous prime is 21965149. The next prime is 21965219. The reversal of 21965151 is 15156912.

It is not a de Polignac number, because 21965151 - 2¹ = 21965149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21965101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8580 + ... + 10841.

It is an arithmetic number, because the mean of its divisors is an integer number (2039310).

Almost surely, 2^21965151 is an apocalyptic number.

21965151 is a deficient number, since it is larger than the sum of its proper divisors (10663809).

21965151 is a wasteful number, since it uses less digits than its factorization.

21965151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19466.

The product of its digits is 2700, while the sum is 30.

The square root of 21965151 is about 4686.6993716260. The cubic root of 21965151 is about 280.0559029537.

It can be divided in two parts, 2 and 1965151, that added together give a triangular number (1965153 = T₁₉₈₂).

The spelling of 21965151 in words is "twenty-one million, nine hundred sixty-five thousand, one hundred fifty-one".