21480155 has 8 divisors (see below), whose sum is σ = 26665200. Its totient is φ = 16591456.

The previous prime is 21480131. The next prime is 21480157. The reversal of 21480155 is 55108412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21480155 - 2¹⁰ = 21479131 is a prime.

It is a super-2 number, since 2×21480155² = 922794117648050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21480157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73925 + ... + 74214.

It is an arithmetic number, because the mean of its divisors is an integer number (3333150).

Almost surely, 2^21480155 is an apocalyptic number.

21480155 is a deficient number, since it is larger than the sum of its proper divisors (5185045).

21480155 is a wasteful number, since it uses less digits than its factorization.

21480155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148173.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 21480155 is about 4634.6688123317. The cubic root of 21480155 is about 277.9793085371.

Adding to 21480155 its reverse (55108412), we get a palindrome (76588567).

The spelling of 21480155 in words is "twenty-one million, four hundred eighty thousand, one hundred fifty-five".