21536940 has 48 divisors (see below), whose sum is σ = 62254080. Its totient is φ = 5557440.

The previous prime is 21536939. The next prime is 21536953. The reversal of 21536940 is 4963512.

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 = 21536898 and 21536907.

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, 3930 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (1296960).

Almost surely, 2^21536940 is an apocalyptic number.

21536940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21536940 is an abundant number, since it is smaller than the sum of its proper divisors (40717140).

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

21536940 is a wasteful number, since it uses less digits than its factorization.

21536940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11622 (or 11620 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 21536940 is about 4640.7908808736. The cubic root of 21536940 is about 278.2240486336.

The spelling of 21536940 in words is "twenty-one million, five hundred thirty-six thousand, nine hundred forty".