70021 has 6 divisors (see below), whose sum is σ = 81510. Its totient is φ = 59976.

The previous prime is 70019. The next prime is 70039. The reversal of 70021 is 12007.

It can be written as a sum of positive squares in only one way, i.e., 44100 + 25921 = 210^2 + 161^2 .

It is not a de Polignac number, because 70021 - 2¹ = 70019 is a prime.

It is a Duffinian number.

70021 is a modest number, since divided by 21 gives 7 as remainder.

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 666 + ... + 763.

It is an arithmetic number, because the mean of its divisors is an integer number (13585).

2⁷⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

70021 is a deficient number, since it is larger than the sum of its proper divisors (11489).

70021 is a wasteful number, since it uses less digits than its factorization.

70021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443 (or 1436 counting only the distinct ones).

The product of its (nonzero) digits is 14, while the sum is 10.

The square root of 70021 is about 264.6148144001. The cubic root of 70021 is about 41.2169738713.

Subtracting from 70021 its product of nonzero digits (14), we obtain a palindrome (70007).

Adding to 70021 its reverse (12007), we get a palindrome (82028).

The spelling of 70021 in words is "seventy thousand, twenty-one", and thus it is an iban number.