21712154 has 16 divisors (see below), whose sum is σ = 33224256. Its totient is φ = 10639200.

The previous prime is 21712153. The next prime is 21712169. The reversal of 21712154 is 45121712.

It is not an unprimeable number, because it can be changed into a prime (21712151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41414 + ... + 41934.

It is an arithmetic number, because the mean of its divisors is an integer number (2076516).

Almost surely, 2^21712154 is an apocalyptic number.

21712154 is a deficient number, since it is larger than the sum of its proper divisors (11512102).

21712154 is a wasteful number, since it uses less digits than its factorization.

21712154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901.

The product of its digits is 560, while the sum is 23.

The square root of 21712154 is about 4659.6302428412. The cubic root of 21712154 is about 278.9765099719.

Adding to 21712154 its reverse (45121712), we get a palindrome (66833866).

The spelling of 21712154 in words is "twenty-one million, seven hundred twelve thousand, one hundred fifty-four".