90561751981 has 8 divisors (see below), whose sum is σ = 95458226720. Its totient is φ = 85678283952.

The previous prime is 90561751967. The next prime is 90561752069. The reversal of 90561751981 is 18915716509.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90561751981 - 2⁷ = 90561751853 is a prime.

It is a super-3 number, since 3×90561751981³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90561751961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3237375 + ... + 3265228.

It is an arithmetic number, because the mean of its divisors is an integer number (11932278340).

Almost surely, 2^90561751981 is an apocalyptic number.

It is an amenable number.

90561751981 is a deficient number, since it is larger than the sum of its proper divisors (4896474739).

90561751981 is a wasteful number, since it uses less digits than its factorization.

90561751981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6503355.

The product of its (nonzero) digits is 680400, while the sum is 52.

The spelling of 90561751981 in words is "ninety billion, five hundred sixty-one million, seven hundred fifty-one thousand, nine hundred eighty-one".