66491646 has 16 divisors (see below), whose sum is σ = 143212944. Its totient is φ = 20458944.

The previous prime is 66491639. The next prime is 66491651. The reversal of 66491646 is 64619466.

It is a super-2 number, since 2×66491646² = 8842277975578632, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66491598 and 66491607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 426151 + ... + 426306.

It is an arithmetic number, because the mean of its divisors is an integer number (8950809).

Almost surely, 2^66491646 is an apocalyptic number.

66491646 is an abundant number, since it is smaller than the sum of its proper divisors (76721298).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66491646 is a wasteful number, since it uses less digits than its factorization.

66491646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852475.

The product of its digits is 186624, while the sum is 42.

The square root of 66491646 is about 8154.2409824581. The cubic root of 66491646 is about 405.1249850495.

The spelling of 66491646 in words is "sixty-six million, four hundred ninety-one thousand, six hundred forty-six".