21949140 has 48 divisors (see below), whose sum is σ = 63124992. Its totient is φ = 5694336.

The previous prime is 21949139. The next prime is 21949163. The reversal of 21949140 is 4194912.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21949098 and 21949107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2724 + ... + 7163.

It is an arithmetic number, because the mean of its divisors is an integer number (1315104).

Almost surely, 2^21949140 is an apocalyptic number.

21949140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21949140 is an abundant number, since it is smaller than the sum of its proper divisors (41175852).

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

21949140 is a wasteful number, since it uses less digits than its factorization.

21949140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9936 (or 9934 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 21949140 is about 4684.9909284864. The cubic root of 21949140 is about 279.9878396079.

The spelling of 21949140 in words is "twenty-one million, nine hundred forty-nine thousand, one hundred forty".