70921809 has 24 divisors (see below), whose sum is σ = 117686400. Its totient is φ = 40315968.

The previous prime is 70921801. The next prime is 70921817. The reversal of 70921809 is 90812907.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (70921801) and next prime (70921817).

It is not a de Polignac number, because 70921809 - 2³ = 70921801 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (70921801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9709 + ... + 15365.

It is an arithmetic number, because the mean of its divisors is an integer number (4903600).

Almost surely, 2^70921809 is an apocalyptic number.

It is an amenable number.

70921809 is a deficient number, since it is larger than the sum of its proper divisors (46764591).

70921809 is a wasteful number, since it uses less digits than its factorization.

70921809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5869 (or 5866 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 70921809 is about 8421.5087128139. The cubic root of 70921809 is about 413.9297122150.

The spelling of 70921809 in words is "seventy million, nine hundred twenty-one thousand, eight hundred nine".