154213970921 has 4 divisors (see below), whose sum is σ = 154366206852. Its totient is φ = 154061734992.

The previous prime is 154213970917. The next prime is 154213970971. The reversal of 154213970921 is 129079312451.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129079312451 = 1229 ⋅105027919.

It can be written as a sum of positive squares in 2 ways, for example, as 13015387225 + 141198583696 = 114085^2 + 375764^2 .

It is a cyclic number.

It is not a de Polignac number, because 154213970921 - 2² = 154213970917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (154213970971) 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, 76116446 + ... + 76118471.

It is an arithmetic number, because the mean of its divisors is an integer number (38591551713).

Almost surely, 2^154213970921 is an apocalyptic number.

It is an amenable number.

154213970921 is a deficient number, since it is larger than the sum of its proper divisors (152235931).

154213970921 is a wasteful number, since it uses less digits than its factorization.

154213970921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152235930.

The product of its (nonzero) digits is 136080, while the sum is 44.

The spelling of 154213970921 in words is "one hundred fifty-four billion, two hundred thirteen million, nine hundred seventy thousand, nine hundred twenty-one".