70280821 has 4 divisors (see below), whose sum is σ = 75687052. Its totient is φ = 64874592.

The previous prime is 70280807. The next prime is 70280857. The reversal of 70280821 is 12808207.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12808207 = 593 ⋅21599.

It can be written as a sum of positive squares in 2 ways, for example, as 18584721 + 51696100 = 4311^2 + 7190^2 .

It is a cyclic number.

It is not a de Polignac number, because 70280821 - 2¹⁵ = 70248053 is a prime.

It is a super-4 number, since 4×70280821⁴ (a number of 32 digits) contains 4444 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 70280821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70280921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2703096 + ... + 2703121.

It is an arithmetic number, because the mean of its divisors is an integer number (18921763).

Almost surely, 2^70280821 is an apocalyptic number.

It is an amenable number.

70280821 is a deficient number, since it is larger than the sum of its proper divisors (5406231).

70280821 is a wasteful number, since it uses less digits than its factorization.

70280821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5406230.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 70280821 is about 8383.3657322104. The cubic root of 70280821 is about 412.6789105761.

The spelling of 70280821 in words is "seventy million, two hundred eighty thousand, eight hundred twenty-one".