21477477 has 16 divisors (see below), whose sum is σ = 34653312. Its totient is φ = 11550720.

The previous prime is 21477461. The next prime is 21477497. The reversal of 21477477 is 77477412.

It is not a de Polignac number, because 21477477 - 2⁴ = 21477461 is a prime.

It is a super-2 number, since 2×21477477² = 922564036571058, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477497) 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 15 ways as a sum of consecutive naturals, for example, 29724 + ... + 30437.

It is an arithmetic number, because the mean of its divisors is an integer number (2165832).

Almost surely, 2^21477477 is an apocalyptic number.

It is an amenable number.

21477477 is a deficient number, since it is larger than the sum of its proper divisors (13175835).

21477477 is a wasteful number, since it uses less digits than its factorization.

21477477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60188.

The product of its digits is 76832, while the sum is 39.

The square root of 21477477 is about 4634.3798937938. The cubic root of 21477477 is about 277.9677558655.

The spelling of 21477477 in words is "twenty-one million, four hundred seventy-seven thousand, four hundred seventy-seven".