21961782 has 12 divisors (see below), whose sum is σ = 47583900. Its totient is φ = 7320588.

The previous prime is 21961781. The next prime is 21961783. The reversal of 21961782 is 28716912.

It is an interprime number because it is at equal distance from previous prime (21961781) and next prime (21961783).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21961781) 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 5 ways as a sum of consecutive naturals, for example, 610032 + ... + 610067.

It is an arithmetic number, because the mean of its divisors is an integer number (3965325).

Almost surely, 2^21961782 is an apocalyptic number.

21961782 is an abundant number, since it is smaller than the sum of its proper divisors (25622118).

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

21961782 is a wasteful number, since it uses less digits than its factorization.

21961782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220107 (or 1220104 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21961782 is about 4686.3399364536. The cubic root of 21961782 is about 280.0415839599.

It can be divided in two parts, 219 and 61782, that added together give a square (62001 = 249²).

The spelling of 21961782 in words is "twenty-one million, nine hundred sixty-one thousand, seven hundred eighty-two".