64640619 has 8 divisors (see below), whose sum is σ = 95763920. Its totient is φ = 43093728.

The previous prime is 64640593. The next prime is 64640621. The reversal of 64640619 is 91604646.

64640619 is a `hidden beast` number, since 6 + 4 + 640 + 6 + 1 + 9 = 666.

It is not a de Polignac number, because 64640619 - 2¹⁷ = 64509547 is a prime.

It is a super-2 number, since 2×64640619² = 8356819249406322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64640669) 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, 1197022 + ... + 1197075.

It is an arithmetic number, because the mean of its divisors is an integer number (11970490).

Almost surely, 2^64640619 is an apocalyptic number.

64640619 is a deficient number, since it is larger than the sum of its proper divisors (31123301).

64640619 is a wasteful number, since it uses less digits than its factorization.

64640619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394106 (or 2394100 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 64640619 is about 8039.9389923058. The cubic root of 64640619 is about 401.3301944699.

The spelling of 64640619 in words is "sixty-four million, six hundred forty thousand, six hundred nineteen".