21655036 has 12 divisors (see below), whose sum is σ = 40811512. Its totient is φ = 9994608.

The previous prime is 21655033. The next prime is 21655037. The reversal of 21655036 is 63055612.

It is a super-2 number, since 2×21655036² = 937881168322592, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21654995 and 21655013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208170 + ... + 208273.

Almost surely, 2^21655036 is an apocalyptic number.

21655036 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21655036 is a deficient number, since it is larger than the sum of its proper divisors (19156476).

21655036 is a wasteful number, since it uses less digits than its factorization.

21655036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416460 (or 416458 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 21655036 is about 4653.4971795414. The cubic root of 21655036 is about 278.7316613379.

The spelling of 21655036 in words is "twenty-one million, six hundred fifty-five thousand, thirty-six".