21475634 has 4 divisors (see below), whose sum is σ = 32213454. Its totient is φ = 10737816.

The previous prime is 21475633. The next prime is 21475637. The reversal of 21475634 is 43657412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20748025 + 727609 = 4555^2 + 853^2 .

It is a super-2 number, since 2×21475634² = 922405711403912, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21475634.

It is not an unprimeable number, because it can be changed into a prime (21475633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5368907 + ... + 5368910.

Almost surely, 2^21475634 is an apocalyptic number.

21475634 is a deficient number, since it is larger than the sum of its proper divisors (10737820).

21475634 is a wasteful number, since it uses less digits than its factorization.

21475634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10737819.

The product of its digits is 20160, while the sum is 32.

The square root of 21475634 is about 4634.1810495491. The cubic root of 21475634 is about 277.9598047574.

The spelling of 21475634 in words is "twenty-one million, four hundred seventy-five thousand, six hundred thirty-four".