66521642 has 16 divisors (see below), whose sum is σ = 109276992. Its totient is φ = 30119520.

The previous prime is 66521617. The next prime is 66521657. The reversal of 66521642 is 24612566.

It is a junction number, because it is equal to n+sod(n) for n = 66521599 and 66521608.

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, 38 + ... + 11534.

It is an arithmetic number, because the mean of its divisors is an integer number (6829812).

Almost surely, 2^66521642 is an apocalyptic number.

66521642 is a deficient number, since it is larger than the sum of its proper divisors (42755350).

66521642 is a wasteful number, since it uses less digits than its factorization.

66521642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11773.

The product of its digits is 17280, while the sum is 32.

The square root of 66521642 is about 8156.0800633638. The cubic root of 66521642 is about 405.1858964715.

The spelling of 66521642 in words is "sixty-six million, five hundred twenty-one thousand, six hundred forty-two".