1554540021 has 12 divisors (see below), whose sum is σ = 2246156640. Its totient is φ = 1036032360.

The previous prime is 1554540019. The next prime is 1554540047. The reversal of 1554540021 is 1200454551.

It is not a de Polignac number, because 1554540021 - 2¹ = 1554540019 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1554540011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4720 + ... + 55958.

It is an arithmetic number, because the mean of its divisors is an integer number (187179720).

Almost surely, 2^1554540021 is an apocalyptic number.

It is an amenable number.

1554540021 is a deficient number, since it is larger than the sum of its proper divisors (691616619).

1554540021 is a wasteful number, since it uses less digits than its factorization.

1554540021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54616 (or 54613 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The square root of 1554540021 is about 39427.6555351697. The cubic root of 1554540021 is about 1158.4233487499.

Adding to 1554540021 its reverse (1200454551), we get a palindrome (2754994572).

The spelling of 1554540021 in words is "one billion, five hundred fifty-four million, five hundred forty thousand, twenty-one".