15650009981 has 2 divisors, whose sum is σ = 15650009982. Its totient is φ = 15650009980.

The previous prime is 15650009959. The next prime is 15650010011. The reversal of 15650009981 is 18990005651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12530787481 + 3119222500 = 111941^2 + 55850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15650009981 is a prime.

It is a super-3 number, since 3×15650009981³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15650009911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7825004990 + 7825004991.

It is an arithmetic number, because the mean of its divisors is an integer number (7825004991).

Almost surely, 2^15650009981 is an apocalyptic number.

It is an amenable number.

15650009981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15650009981 is an equidigital number, since it uses as much as digits as its factorization.

15650009981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 44.

The spelling of 15650009981 in words is "fifteen billion, six hundred fifty million, nine thousand, nine hundred eighty-one".