42640646 has 4 divisors (see below), whose sum is σ = 63960972. Its totient is φ = 21320322.

The previous prime is 42640639. The next prime is 42640651. The reversal of 42640646 is 64604624.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660160 + ... + 10660163.

It is an arithmetic number, because the mean of its divisors is an integer number (15990243).

Almost surely, 2^42640646 is an apocalyptic number.

42640646 is a deficient number, since it is larger than the sum of its proper divisors (21320326).

42640646 is a wasteful number, since it uses less digits than its factorization.

42640646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21320325.

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 42640646 is about 6529.9805512727. The cubic root of 42640646 is about 349.3611366177.

The spelling of 42640646 in words is "forty-two million, six hundred forty thousand, six hundred forty-six".