664147749481 has 16 divisors (see below), whose sum is σ = 689251673088. Its totient is φ = 639275716800.

The previous prime is 664147749431. The next prime is 664147749511. The reversal of 664147749481 is 184947741466.

It is not a de Polignac number, because 664147749481 - 2¹⁹ = 664147225193 is a prime.

It is a super-2 number, since 2×664147749481² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

Its product of digits (32514048) is a multiple of the sum of its prime divisors (31752).

It is not an unprimeable number, because it can be changed into a prime (664147749431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24066111 + ... + 24093691.

It is an arithmetic number, because the mean of its divisors is an integer number (43078229568).

Almost surely, 2^664147749481 is an apocalyptic number.

It is an amenable number.

664147749481 is a deficient number, since it is larger than the sum of its proper divisors (25103923607).

664147749481 is a wasteful number, since it uses less digits than its factorization.

664147749481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31752.

The product of its digits is 32514048, while the sum is 61.

The spelling of 664147749481 in words is "six hundred sixty-four billion, one hundred forty-seven million, seven hundred forty-nine thousand, four hundred eighty-one".