65554001981 has 8 divisors (see below), whose sum is σ = 70704737880. Its totient is φ = 60418711872.

The previous prime is 65554001969. The next prime is 65554002001. The reversal of 65554001981 is 18910045556.

65554001981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 97337956 + 65456664025 = 9866^2 + 255845^2 .

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 65554001981 - 2⁶ = 65554001917 is a prime.

It is a super-2 number, since 2×65554001981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65554001911) 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, 3852626 + ... + 3869603.

It is an arithmetic number, because the mean of its divisors is an integer number (8838092235).

Almost surely, 2^65554001981 is an apocalyptic number.

It is an amenable number.

65554001981 is a deficient number, since it is larger than the sum of its proper divisors (5150735899).

65554001981 is a wasteful number, since it uses less digits than its factorization.

65554001981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7722895.

The product of its (nonzero) digits is 216000, while the sum is 44.

The spelling of 65554001981 in words is "sixty-five billion, five hundred fifty-four million, one thousand, nine hundred eighty-one".