21650046661 has 2 divisors, whose sum is σ = 21650046662. Its totient is φ = 21650046660.

The previous prime is 21650046623. The next prime is 21650046697. The reversal of 21650046661 is 16664005612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19826329636 + 1823717025 = 140806^2 + 42705^2 .

It is a cyclic number.

It is not a de Polignac number, because 21650046661 - 2¹³ = 21650038469 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21650046661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21650041661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10825023330 + 10825023331.

It is an arithmetic number, because the mean of its divisors is an integer number (10825023331).

Almost surely, 2^21650046661 is an apocalyptic number.

It is an amenable number.

21650046661 is a deficient number, since it is larger than the sum of its proper divisors (1).

21650046661 is an equidigital number, since it uses as much as digits as its factorization.

21650046661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21650046661 in words is "twenty-one billion, six hundred fifty million, forty-six thousand, six hundred sixty-one".