42777621 has 12 divisors (see below), whose sum is σ = 62021440. Its totient is φ = 28411560.

The previous prime is 42777617. The next prime is 42777629. The reversal of 42777621 is 12677724.

It is a happy number.

42777621 is a `hidden beast` number, since 4 + 27 + 7 + 7 + 621 = 666.

It is not a de Polignac number, because 42777621 - 2² = 42777617 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 (42777629) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6331 + ... + 11208.

Almost surely, 2^42777621 is an apocalyptic number.

It is an amenable number.

42777621 is a deficient number, since it is larger than the sum of its proper divisors (19243819).

42777621 is a wasteful number, since it uses less digits than its factorization.

42777621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17816 (or 17813 counting only the distinct ones).

The product of its digits is 32928, while the sum is 36.

The square root of 42777621 is about 6540.4603049021. The cubic root of 42777621 is about 349.7348222679.

The spelling of 42777621 in words is "forty-two million, seven hundred seventy-seven thousand, six hundred twenty-one".