66632621 has 4 divisors (see below), whose sum is σ = 72690144. Its totient is φ = 60575100.

The previous prime is 66632611. The next prime is 66632659. The reversal of 66632621 is 12623666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66632621 - 2²² = 62438317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66632611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3028745 + ... + 3028766.

It is an arithmetic number, because the mean of its divisors is an integer number (18172536).

Almost surely, 2^66632621 is an apocalyptic number.

It is an amenable number.

66632621 is a deficient number, since it is larger than the sum of its proper divisors (6057523).

66632621 is a wasteful number, since it uses less digits than its factorization.

66632621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6057522.

The product of its digits is 15552, while the sum is 32.

The square root of 66632621 is about 8162.8806802501. The cubic root of 66632621 is about 405.4110970778.

The spelling of 66632621 in words is "sixty-six million, six hundred thirty-two thousand, six hundred twenty-one".