65628981 has 16 divisors (see below), whose sum is σ = 106067520. Its totient is φ = 39774960.

The previous prime is 65628973. The next prime is 65628991. The reversal of 65628981 is 18982656.

65628981 is a `hidden beast` number, since 6 + 562 + 8 + 9 + 81 = 666.

It is not a de Polignac number, because 65628981 - 2³ = 65628973 is a prime.

It is a super-2 number, since 2×65628981² = 8614326294196722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65628961) 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, 110190 + ... + 110783.

It is an arithmetic number, because the mean of its divisors is an integer number (6629220).

Almost surely, 2^65628981 is an apocalyptic number.

It is an amenable number.

65628981 is a deficient number, since it is larger than the sum of its proper divisors (40438539).

65628981 is a wasteful number, since it uses less digits than its factorization.

65628981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220993 (or 220987 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 65628981 is about 8101.1715819380. The cubic root of 65628981 is about 403.3653176072.

The spelling of 65628981 in words is "sixty-five million, six hundred twenty-eight thousand, nine hundred eighty-one".