64440426999 has 32 divisors (see below), whose sum is σ = 98166906880. Its totient is φ = 37272638592.

The previous prime is 64440426943. The next prime is 64440427013. The reversal of 64440426999 is 99962404446.

It is a happy number.

It is not a de Polignac number, because 64440426999 - 2¹⁹ = 64439902711 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64440426499) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 248272 + ... + 436485.

It is an arithmetic number, because the mean of its divisors is an integer number (3067715840).

Almost surely, 2^64440426999 is an apocalyptic number.

64440426999 is a deficient number, since it is larger than the sum of its proper divisors (33726479881).

64440426999 is a wasteful number, since it uses less digits than its factorization.

64440426999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684919.

The product of its (nonzero) digits is 13436928, while the sum is 57.

The spelling of 64440426999 in words is "sixty-four billion, four hundred forty million, four hundred twenty-six thousand, nine hundred ninety-nine".