70906821 has 4 divisors (see below), whose sum is σ = 94542432. Its totient is φ = 47271212.

The previous prime is 70906811. The next prime is 70906853. The reversal of 70906821 is 12860907.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12860907 = 3 ⋅4286969.

It is a cyclic number.

It is not a de Polignac number, because 70906821 - 2²¹ = 68809669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70906811) 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, 11817801 + ... + 11817806.

It is an arithmetic number, because the mean of its divisors is an integer number (23635608).

Almost surely, 2^70906821 is an apocalyptic number.

It is an amenable number.

70906821 is a deficient number, since it is larger than the sum of its proper divisors (23635611).

70906821 is a wasteful number, since it uses less digits than its factorization.

70906821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23635610.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 70906821 is about 8420.6188014896. The cubic root of 70906821 is about 413.9005513889.

The spelling of 70906821 in words is "seventy million, nine hundred six thousand, eight hundred twenty-one".