21477474 has 40 divisors (see below), whose sum is σ = 48416940. Its totient is φ = 7115904.

The previous prime is 21477461. The next prime is 21477497. The reversal of 21477474 is 47477412.

It can be written as a sum of positive squares in 2 ways, for example, as 19053225 + 2424249 = 4365^2 + 1557^2 .

It is a super-2 number, since 2×21477474² = 922563778841352, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 37462 + ... + 38030.

Almost surely, 2^21477474 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21477474, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24208470).

21477474 is an abundant number, since it is smaller than the sum of its proper divisors (26939466).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21477474 is a wasteful number, since it uses less digits than its factorization.

21477474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816 (or 807 counting only the distinct ones).

The product of its digits is 43904, while the sum is 36.

The square root of 21477474 is about 4634.3795701259. The cubic root of 21477474 is about 277.9677429232.

The spelling of 21477474 in words is "twenty-one million, four hundred seventy-seven thousand, four hundred seventy-four".