21821763730 has 16 divisors (see below), whose sum is σ = 42300649944. Its totient is φ = 8057266560.

The previous prime is 21821763721. The next prime is 21821763749. The reversal of 21821763730 is 3736712812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17600532889 + 4221230841 = 132667^2 + 64971^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83929731 + ... + 83929990.

Almost surely, 2^21821763730 is an apocalyptic number.

21821763730 is a deficient number, since it is larger than the sum of its proper divisors (20478886214).

21821763730 is a wasteful number, since it uses less digits than its factorization.

21821763730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167859741.

The product of its (nonzero) digits is 84672, while the sum is 40.

The spelling of 21821763730 in words is "twenty-one billion, eight hundred twenty-one million, seven hundred sixty-three thousand, seven hundred thirty".