1550421553 has 4 divisors (see below), whose sum is σ = 1550570608. Its totient is φ = 1550272500.

The previous prime is 1550421511. The next prime is 1550421617. The reversal of 1550421553 is 3551240551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1550421553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1550421953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57651 + ... + 80152.

It is an arithmetic number, because the mean of its divisors is an integer number (387642652).

Almost surely, 2^1550421553 is an apocalyptic number.

It is an amenable number.

1550421553 is a deficient number, since it is larger than the sum of its proper divisors (149055).

1550421553 is a wasteful number, since it uses less digits than its factorization.

1550421553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149054.

The product of its (nonzero) digits is 15000, while the sum is 31.

The square root of 1550421553 is about 39375.3927345493. The cubic root of 1550421553 is about 1157.3994340928.

The spelling of 1550421553 in words is "one billion, five hundred fifty million, four hundred twenty-one thousand, five hundred fifty-three".