913221857 has 4 divisors (see below), whose sum is σ = 913295040. Its totient is φ = 913148676.

The previous prime is 913221851. The next prime is 913221889. The reversal of 913221857 is 758122319.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 758122319 = 8389 ⋅90371.

It is a cyclic number.

It is not a de Polignac number, because 913221857 - 2¹² = 913217761 is a prime.

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 913221857.

It is not an unprimeable number, because it can be changed into a prime (913221851) 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, 12653 + ... + 44570.

It is an arithmetic number, because the mean of its divisors is an integer number (228323760).

Almost surely, 2^913221857 is an apocalyptic number.

It is an amenable number.

913221857 is a deficient number, since it is larger than the sum of its proper divisors (73183).

913221857 is a wasteful number, since it uses less digits than its factorization.

913221857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73182.

The product of its digits is 30240, while the sum is 38.

The square root of 913221857 is about 30219.5608340029. The cubic root of 913221857 is about 970.1944050073.

The spelling of 913221857 in words is "nine hundred thirteen million, two hundred twenty-one thousand, eight hundred fifty-seven".