21191960 has 32 divisors (see below), whose sum is σ = 47820240. Its totient is φ = 8452224.

The previous prime is 21191959. The next prime is 21191969. The reversal of 21191960 is 6919112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20414 + ... + 21426.

Almost surely, 2^21191960 is an apocalyptic number.

21191960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21191960 is an abundant number, since it is smaller than the sum of its proper divisors (26628280).

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

21191960 is a wasteful number, since it uses less digits than its factorization.

21191960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547 (or 1543 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 29.

The square root of 21191960 is about 4603.4726022862. The cubic root of 21191960 is about 276.7305089681.

The spelling of 21191960 in words is "twenty-one million, one hundred ninety-one thousand, nine hundred sixty".