21477197 has 16 divisors (see below), whose sum is σ = 25555200. Its totient is φ = 17660160.

The previous prime is 21477179. The next prime is 21477199. The reversal of 21477197 is 79177412.

It is not a de Polignac number, because 21477197 - 2⁶ = 21477133 is a prime.

It is a super-2 number, since 2×21477197² = 922539981953618, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21477197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477199) 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, 48704 + ... + 49142.

It is an arithmetic number, because the mean of its divisors is an integer number (1597200).

Almost surely, 2^21477197 is an apocalyptic number.

It is an amenable number.

21477197 is a deficient number, since it is larger than the sum of its proper divisors (4078003).

21477197 is a wasteful number, since it uses less digits than its factorization.

21477197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716.

The product of its digits is 24696, while the sum is 38.

The square root of 21477197 is about 4634.3496846915. The cubic root of 21477197 is about 277.9665479131.

The spelling of 21477197 in words is "twenty-one million, four hundred seventy-seven thousand, one hundred ninety-seven".