870221391 has 12 divisors (see below), whose sum is σ = 1256415048. Its totient is φ = 535520544.

The previous prime is 870221383. The next prime is 870221423. The reversal of 870221391 is 193122078.

It is not a de Polignac number, because 870221391 - 2³ = 870221383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (870220391) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 857700 + ... + 858713.

It is an arithmetic number, because the mean of its divisors is an integer number (104701254).

Almost surely, 2^870221391 is an apocalyptic number.

870221391 is a deficient number, since it is larger than the sum of its proper divisors (386193657).

870221391 is a wasteful number, since it uses less digits than its factorization.

870221391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716442 (or 1716429 counting only the distinct ones).

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

The square root of 870221391 is about 29499.5150977097. The cubic root of 870221391 is about 954.7212406062.

The spelling of 870221391 in words is "eight hundred seventy million, two hundred twenty-one thousand, three hundred ninety-one".