65445981 has 4 divisors (see below), whose sum is σ = 87261312. Its totient is φ = 43630652.

The previous prime is 65445979. The next prime is 65445983. The reversal of 65445981 is 18954456.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (65445979) and next prime (65445983).

It is a cyclic number.

It is not a de Polignac number, because 65445981 - 2¹ = 65445979 is a prime.

It is a super-2 number, since 2×65445981² = 8566352858104722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65445983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10907661 + ... + 10907666.

It is an arithmetic number, because the mean of its divisors is an integer number (21815328).

Almost surely, 2^65445981 is an apocalyptic number.

It is an amenable number.

65445981 is a deficient number, since it is larger than the sum of its proper divisors (21815331).

65445981 is a wasteful number, since it uses less digits than its factorization.

65445981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21815330.

The product of its digits is 172800, while the sum is 42.

The square root of 65445981 is about 8089.8690347867. The cubic root of 65445981 is about 402.9900536719.

The spelling of 65445981 in words is "sixty-five million, four hundred forty-five thousand, nine hundred eighty-one".