21080157 has 8 divisors (see below), whose sum is σ = 32122176. Its totient is φ = 12045792.

The previous prime is 21080149. The next prime is 21080159. The reversal of 21080157 is 75108012.

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

It is not a de Polignac number, because 21080157 - 2³ = 21080149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080159) 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, 501888 + ... + 501929.

It is an arithmetic number, because the mean of its divisors is an integer number (4015272).

Almost surely, 2^21080157 is an apocalyptic number.

It is an amenable number.

21080157 is a deficient number, since it is larger than the sum of its proper divisors (11042019).

21080157 is a wasteful number, since it uses less digits than its factorization.

21080157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003827.

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 21080157 is about 4591.3132108363. The cubic root of 21080157 is about 276.2429990787.

Adding to 21080157 its reverse (75108012), we get a palindrome (96188169).

The spelling of 21080157 in words is "twenty-one million, eighty thousand, one hundred fifty-seven".