21194151 has 8 divisors (see below), whose sum is σ = 30827904. Its totient is φ = 12844920.

The previous prime is 21194149. The next prime is 21194197. The reversal of 21194151 is 15149112.

It is a happy number.

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

It is not a de Polignac number, because 21194151 - 2¹ = 21194149 is a prime.

It is a super-2 number, since 2×21194151² = 898384073221602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21194351) 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, 321091 + ... + 321156.

It is an arithmetic number, because the mean of its divisors is an integer number (3853488).

Almost surely, 2^21194151 is an apocalyptic number.

21194151 is a deficient number, since it is larger than the sum of its proper divisors (9633753).

21194151 is a wasteful number, since it uses less digits than its factorization.

21194151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642261.

The product of its digits is 360, while the sum is 24.

The square root of 21194151 is about 4603.7105686609. The cubic root of 21194151 is about 276.7400455353.

The spelling of 21194151 in words is "twenty-one million, one hundred ninety-four thousand, one hundred fifty-one".