64502981 has 8 divisors (see below), whose sum is σ = 68471640. Its totient is φ = 60553728.

The previous prime is 64502957. The next prime is 64502987. The reversal of 64502981 is 18920546.

It can be written as a sum of positive squares in 4 ways, for example, as 43112356 + 21390625 = 6566^2 + 4625^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64502981 - 2¹⁸ = 64240837 is a prime.

It is a super-2 number, since 2×64502981² = 8321269115772722, 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 (64502987) 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, 2315 + ... + 11591.

It is an arithmetic number, because the mean of its divisors is an integer number (8558955).

Almost surely, 2^64502981 is an apocalyptic number.

It is an amenable number.

64502981 is a deficient number, since it is larger than the sum of its proper divisors (3968659).

64502981 is a wasteful number, since it uses less digits than its factorization.

64502981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9703.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 64502981 is about 8031.3747889138. The cubic root of 64502981 is about 401.0451438905.

The spelling of 64502981 in words is "sixty-four million, five hundred two thousand, nine hundred eighty-one".