70821491 has 4 divisors (see below), whose sum is σ = 76269312. Its totient is φ = 65373672.

The previous prime is 70821469. The next prime is 70821497. The reversal of 70821491 is 19412807.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 70821491 - 2²⁶ = 3712627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70821497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2723891 + ... + 2723916.

It is an arithmetic number, because the mean of its divisors is an integer number (19067328).

Almost surely, 2^70821491 is an apocalyptic number.

70821491 is a deficient number, since it is larger than the sum of its proper divisors (5447821).

70821491 is a wasteful number, since it uses less digits than its factorization.

70821491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5447820.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 70821491 is about 8415.5505464586. The cubic root of 70821491 is about 413.7344540120.

The spelling of 70821491 in words is "seventy million, eight hundred twenty-one thousand, four hundred ninety-one".