21969562 has 4 divisors (see below), whose sum is σ = 32954346. Its totient is φ = 10984780.

The previous prime is 21969557. The next prime is 21969581. The reversal of 21969562 is 26596912.

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., 21818241 + 151321 = 4671^2 + 389^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5492389 + ... + 5492392.

Almost surely, 2^21969562 is an apocalyptic number.

21969562 is a deficient number, since it is larger than the sum of its proper divisors (10984784).

21969562 is a wasteful number, since it uses less digits than its factorization.

21969562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10984783.

The product of its digits is 58320, while the sum is 40.

The square root of 21969562 is about 4687.1699350461. The cubic root of 21969562 is about 280.0746484642.

The spelling of 21969562 in words is "twenty-one million, nine hundred sixty-nine thousand, five hundred sixty-two".