21411590661 has 36 divisors (see below), whose sum is σ = 33036396484. Its totient is φ = 13360204800.

The previous prime is 21411590659. The next prime is 21411590693. The reversal of 21411590661 is 16609511412.

21411590661 is a `hidden beast` number, since 2 + 1 + 4 + 1 + 1 + 590 + 6 + 61 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 2862785025 + 18548805636 = 53505^2 + 136194^2 .

It is not a de Polignac number, because 21411590661 - 2¹ = 21411590659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21411591661) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 448041 + ... + 493521.

Almost surely, 2^21411590661 is an apocalyptic number.

It is an amenable number.

21411590661 is a deficient number, since it is larger than the sum of its proper divisors (11624805823).

21411590661 is a wasteful number, since it uses less digits than its factorization.

21411590661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45702 (or 45682 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The spelling of 21411590661 in words is "twenty-one billion, four hundred eleven million, five hundred ninety thousand, six hundred sixty-one".