64651961 has 8 divisors (see below), whose sum is σ = 71523648. Its totient is φ = 57946000.

The previous prime is 64651949. The next prime is 64651963. The reversal of 64651961 is 16915646.

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 64651961 - 2¹⁸ = 64389817 is a prime.

It is a super-2 number, since 2×64651961² = 8359752122291042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64651963) 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, 40610 + ... + 42171.

It is an arithmetic number, because the mean of its divisors is an integer number (8940456).

Almost surely, 2^64651961 is an apocalyptic number.

It is an amenable number.

64651961 is a deficient number, since it is larger than the sum of its proper divisors (6871687).

64651961 is a wasteful number, since it uses less digits than its factorization.

64651961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82863.

The product of its digits is 38880, while the sum is 38.

The square root of 64651961 is about 8040.6443149787. The cubic root of 64651961 is about 401.3536658873.

The spelling of 64651961 in words is "sixty-four million, six hundred fifty-one thousand, nine hundred sixty-one".