55621917 has 32 divisors (see below), whose sum is σ = 89631360. Its totient is φ = 33886080.

The previous prime is 55621903. The next prime is 55621931. The reversal of 55621917 is 71912655.

55621917 is a `hidden beast` number, since 5 + 562 + 1 + 91 + 7 = 666.

55621917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (55621903) and next prime (55621931).

It is not a de Polignac number, because 55621917 - 2⁴ = 55621901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55621997) 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 31 ways as a sum of consecutive naturals, for example, 36817 + ... + 38297.

It is an arithmetic number, because the mean of its divisors is an integer number (2800980).

Almost surely, 2^55621917 is an apocalyptic number.

It is an amenable number.

55621917 is a deficient number, since it is larger than the sum of its proper divisors (34009443).

55621917 is a wasteful number, since it uses less digits than its factorization.

55621917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610 (or 1604 counting only the distinct ones).

The product of its digits is 18900, while the sum is 36.

The square root of 55621917 is about 7458.0102574346. The cubic root of 55621917 is about 381.7232835121.

The spelling of 55621917 in words is "fifty-five million, six hundred twenty-one thousand, nine hundred seventeen".