64904981 has 4 divisors (see below), whose sum is σ = 65152032. Its totient is φ = 64657932.

The previous prime is 64904953. The next prime is 64905013. The reversal of 64904981 is 18940946.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18940946 = 2 ⋅9470473.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64904981 is a prime.

It is a super-2 number, since 2×64904981² = 8425313117220722, which 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 (64904881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123131 + ... + 123656.

It is an arithmetic number, because the mean of its divisors is an integer number (16288008).

Almost surely, 2^64904981 is an apocalyptic number.

It is an amenable number.

64904981 is a deficient number, since it is larger than the sum of its proper divisors (247051).

64904981 is a wasteful number, since it uses less digits than its factorization.

64904981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247050.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 64904981 is about 8056.3627649207. The cubic root of 64904981 is about 401.8765596261.

The spelling of 64904981 in words is "sixty-four million, nine hundred four thousand, nine hundred eighty-one".