21662251033 has 4 divisors (see below), whose sum is σ = 21876728868. Its totient is φ = 21447773200.

The previous prime is 21662250989. The next prime is 21662251043. The reversal of 21662251033 is 33015226612.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16911181849 + 4751069184 = 130043^2 + 68928^2 .

It is a cyclic number.

It is not a de Polignac number, because 21662251033 - 2¹³ = 21662242841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21662250986 and 21662251004.

It is not an unprimeable number, because it can be changed into a prime (21662251043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107238766 + ... + 107238967.

It is an arithmetic number, because the mean of its divisors is an integer number (5469182217).

Almost surely, 2^21662251033 is an apocalyptic number.

It is an amenable number.

21662251033 is a deficient number, since it is larger than the sum of its proper divisors (214477835).

21662251033 is a wasteful number, since it uses less digits than its factorization.

21662251033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214477834.

The product of its (nonzero) digits is 12960, while the sum is 31.

Adding to 21662251033 its reverse (33015226612), we get a palindrome (54677477645).

The spelling of 21662251033 in words is "twenty-one billion, six hundred sixty-two million, two hundred fifty-one thousand, thirty-three".