154520021 has 16 divisors (see below), whose sum is σ = 169682688. Its totient is φ = 140121600.

The previous prime is 154519999. The next prime is 154520053. The reversal of 154520021 is 120025451.

It is a de Polignac number, because none of the positive numbers 2^k-154520021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 154519975 and 154520002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (154520071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56516 + ... + 59186.

It is an arithmetic number, because the mean of its divisors is an integer number (10605168).

Almost surely, 2^154520021 is an apocalyptic number.

It is an amenable number.

154520021 is a deficient number, since it is larger than the sum of its proper divisors (15162667).

154520021 is a wasteful number, since it uses less digits than its factorization.

154520021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2812.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 154520021 is about 12430.6082312975. The cubic root of 154520021 is about 536.6134898808.

Adding to 154520021 its reverse (120025451), we get a palindrome (274545472).

The spelling of 154520021 in words is "one hundred fifty-four million, five hundred twenty thousand, twenty-one".