47940021 has 12 divisors (see below), whose sum is σ = 72891520. Its totient is φ = 30277800.

The previous prime is 47940007. The next prime is 47940077. The reversal of 47940021 is 12004974.

It is a happy number.

It is not a de Polignac number, because 47940021 - 2⁵ = 47939989 is a prime.

It is a super-2 number, since 2×47940021² = 4596491226960882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47940091) 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, 140005 + ... + 140346.

Almost surely, 2^47940021 is an apocalyptic number.

It is an amenable number.

47940021 is a deficient number, since it is larger than the sum of its proper divisors (24951499).

47940021 is a wasteful number, since it uses less digits than its factorization.

47940021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280376 (or 280373 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 47940021 is about 6923.8732657379. The cubic root of 47940021 is about 363.2726817556.

Adding to 47940021 its reverse (12004974), we get a palindrome (59944995).

The spelling of 47940021 in words is "forty-seven million, nine hundred forty thousand, twenty-one".