55773221 has 12 divisors (see below), whose sum is σ = 65286432. Its totient is φ = 47505528.

The previous prime is 55773203. The next prime is 55773251. The reversal of 55773221 is 12237755.

It is not a de Polignac number, because 55773221 - 2¹⁴ = 55756837 is a prime.

It is a super-2 number, since 2×55773221² = 6221304361429682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55773251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4496 + ... + 11478.

It is an arithmetic number, because the mean of its divisors is an integer number (5440536).

Almost surely, 2^55773221 is an apocalyptic number.

It is an amenable number.

55773221 is a deficient number, since it is larger than the sum of its proper divisors (9513211).

55773221 is a wasteful number, since it uses less digits than its factorization.

55773221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7160 (or 7153 counting only the distinct ones).

The product of its digits is 14700, while the sum is 32.

The square root of 55773221 is about 7468.1470928203. The cubic root of 55773221 is about 382.0690942515.

The spelling of 55773221 in words is "fifty-five million, seven hundred seventy-three thousand, two hundred twenty-one".