21147078 has 16 divisors (see below), whose sum is σ = 42874416. Its totient is φ = 6952320.

The previous prime is 21147073. The next prime is 21147079. The reversal of 21147078 is 87074112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147073) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23703 + ... + 24578.

It is an arithmetic number, because the mean of its divisors is an integer number (2679651).

Almost surely, 2^21147078 is an apocalyptic number.

21147078 is an abundant number, since it is smaller than the sum of its proper divisors (21727338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21147078 is a wasteful number, since it uses less digits than its factorization.

21147078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48359.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 21147078 is about 4598.5952202820. The cubic root of 21147078 is about 276.5350103418.

The spelling of 21147078 in words is "twenty-one million, one hundred forty-seven thousand, seventy-eight".