19530661 has 2 divisors, whose sum is σ = 19530662. Its totient is φ = 19530660.

The previous prime is 19530649. The next prime is 19530683. The reversal of 19530661 is 16603591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18105025 + 1425636 = 4255^2 + 1194^2 .

It is an emirp because it is prime and its reverse (16603591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19530661 - 2¹⁵ = 19497893 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19530631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9765330 + 9765331.

It is an arithmetic number, because the mean of its divisors is an integer number (9765331).

Almost surely, 2^19530661 is an apocalyptic number.

It is an amenable number.

19530661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19530661 is an equidigital number, since it uses as much as digits as its factorization.

19530661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 19530661 is about 4419.3507441705. The cubic root of 19530661 is about 269.3016291078.

The spelling of 19530661 in words is "nineteen million, five hundred thirty thousand, six hundred sixty-one".