42154100921 has 4 divisors (see below), whose sum is σ = 42437014500. Its totient is φ = 41871187344.

The previous prime is 42154100869. The next prime is 42154100957. The reversal of 42154100921 is 12900145124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21384967696 + 20769133225 = 146236^2 + 144115^2 .

It is a cyclic number.

It is not a de Polignac number, because 42154100921 - 2¹⁴ = 42154084537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42154100971) 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, 141456566 + ... + 141456863.

It is an arithmetic number, because the mean of its divisors is an integer number (10609253625).

Almost surely, 2^42154100921 is an apocalyptic number.

It is an amenable number.

42154100921 is a deficient number, since it is larger than the sum of its proper divisors (282913579).

42154100921 is a wasteful number, since it uses less digits than its factorization.

42154100921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282913578.

The product of its (nonzero) digits is 2880, while the sum is 29.

The spelling of 42154100921 in words is "forty-two billion, one hundred fifty-four million, one hundred thousand, nine hundred twenty-one".