28311409661 has 4 divisors (see below), whose sum is σ = 28527527424. Its totient is φ = 28095291900.

The previous prime is 28311409601. The next prime is 28311409669. The reversal of 28311409661 is 16690411382.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16690411382 = 2 ⋅8345205691.

It is a cyclic number.

It is not a de Polignac number, because 28311409661 - 2¹⁸ = 28311147517 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 (28311409669) 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, 108058685 + ... + 108058946.

It is an arithmetic number, because the mean of its divisors is an integer number (7131881856).

Almost surely, 2^28311409661 is an apocalyptic number.

It is an amenable number.

28311409661 is a deficient number, since it is larger than the sum of its proper divisors (216117763).

28311409661 is a wasteful number, since it uses less digits than its factorization.

28311409661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216117762.

The product of its (nonzero) digits is 62208, while the sum is 41.

The spelling of 28311409661 in words is "twenty-eight billion, three hundred eleven million, four hundred nine thousand, six hundred sixty-one".