55121221407 has 32 divisors (see below), whose sum is σ = 84271982080. Its totient is φ = 31393837440.

The previous prime is 55121221391. The next prime is 55121221409. The reversal of 55121221407 is 70412212155.

It is a happy number.

It is not a de Polignac number, because 55121221407 - 2⁴ = 55121221391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55121221409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12631608 + ... + 12635970.

It is an arithmetic number, because the mean of its divisors is an integer number (2633499440).

Almost surely, 2^55121221407 is an apocalyptic number.

55121221407 is a deficient number, since it is larger than the sum of its proper divisors (29150760673).

55121221407 is a wasteful number, since it uses less digits than its factorization.

55121221407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6223.

The product of its (nonzero) digits is 5600, while the sum is 30.

The spelling of 55121221407 in words is "fifty-five billion, one hundred twenty-one million, two hundred twenty-one thousand, four hundred seven".