21955461 has 16 divisors (see below), whose sum is σ = 32021568. Its totient is φ = 13270400.

The previous prime is 21955457. The next prime is 21955463. The reversal of 21955461 is 16455912.

It is not a de Polignac number, because 21955461 - 2² = 21955457 is a prime.

It is a super-4 number, since 4×21955461⁴ (a number of 30 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21955463) 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 15 ways as a sum of consecutive naturals, for example, 16555 + ... + 17831.

It is an arithmetic number, because the mean of its divisors is an integer number (2001348).

Almost surely, 2^21955461 is an apocalyptic number.

It is an amenable number.

21955461 is a deficient number, since it is larger than the sum of its proper divisors (10066107).

21955461 is a wasteful number, since it uses less digits than its factorization.

21955461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1812.

The product of its digits is 10800, while the sum is 33.

The square root of 21955461 is about 4685.6654810176. The cubic root of 21955461 is about 280.0147143628.

The spelling of 21955461 in words is "twenty-one million, nine hundred fifty-five thousand, four hundred sixty-one".