55801221 has 8 divisors (see below), whose sum is σ = 85030464. Its totient is φ = 31886400.

The previous prime is 55801211. The next prime is 55801231. The reversal of 55801221 is 12210855.

It is an interprime number because it is at equal distance from previous prime (55801211) and next prime (55801231).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55801221 - 2⁵ = 55801189 is a prime.

It is a super-2 number, since 2×55801221² = 6227552530181682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 55801191 and 55801200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55801201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1328580 + ... + 1328621.

It is an arithmetic number, because the mean of its divisors is an integer number (10628808).

Almost surely, 2^55801221 is an apocalyptic number.

It is an amenable number.

55801221 is a deficient number, since it is larger than the sum of its proper divisors (29229243).

55801221 is a wasteful number, since it uses less digits than its factorization.

55801221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2657211.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 55801221 is about 7470.0214859129. The cubic root of 55801221 is about 382.1330206586.

The spelling of 55801221 in words is "fifty-five million, eight hundred one thousand, two hundred twenty-one".