9958989781 has 16 divisors (see below), whose sum is σ = 10815888384. Its totient is φ = 9115398144.

The previous prime is 9958989779. The next prime is 9958989787. The reversal of 9958989781 is 1879898599.

It is a cyclic number.

It is not a de Polignac number, because 9958989781 - 2¹ = 9958989779 is a prime.

It is a super-2 number, since 2×9958989781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9958989787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 738360 + ... + 751726.

It is an arithmetic number, because the mean of its divisors is an integer number (675993024).

Almost surely, 2^9958989781 is an apocalyptic number.

It is an amenable number.

9958989781 is a deficient number, since it is larger than the sum of its proper divisors (856898603).

9958989781 is a wasteful number, since it uses less digits than its factorization.

9958989781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13860.

The product of its digits is 117573120, while the sum is 73.

The square root of 9958989781 is about 99794.7382430557. The cubic root of 9958989781 is about 2151.4855268740.

The spelling of 9958989781 in words is "nine billion, nine hundred fifty-eight million, nine hundred eighty-nine thousand, seven hundred eighty-one".