70851809 has 4 divisors (see below), whose sum is σ = 80973504. Its totient is φ = 60730116.

The previous prime is 70851797. The next prime is 70851811. The reversal of 70851809 is 90815807.

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.

It is a cyclic number.

It is not a de Polignac number, because 70851809 - 2⁴ = 70851793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70851899) 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, 5060837 + ... + 5060850.

It is an arithmetic number, because the mean of its divisors is an integer number (20243376).

Almost surely, 2^70851809 is an apocalyptic number.

It is an amenable number.

70851809 is a deficient number, since it is larger than the sum of its proper divisors (10121695).

70851809 is a wasteful number, since it uses less digits than its factorization.

70851809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10121694.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 70851809 is about 8417.3516618946. The cubic root of 70851809 is about 413.7934841712.

The spelling of 70851809 in words is "seventy million, eight hundred fifty-one thousand, eight hundred nine".