191021240 has 32 divisors (see below), whose sum is σ = 435857760. Its totient is φ = 75331200.

The previous prime is 191021219. The next prime is 191021267. The reversal of 191021240 is 42120191.

It is a super-2 number, since 2×191021240² = 72978228262275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30791 + ... + 36470.

It is an arithmetic number, because the mean of its divisors is an integer number (13620555).

Almost surely, 2^191021240 is an apocalyptic number.

191021240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191021240 is an abundant number, since it is smaller than the sum of its proper divisors (244836520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191021240 is a wasteful number, since it uses less digits than its factorization.

191021240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67343 (or 67339 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 191021240 is about 13821.0433759539. The cubic root of 191021240 is about 575.9178686264.

The spelling of 191021240 in words is "one hundred ninety-one million, twenty-one thousand, two hundred forty".