21498155 has 16 divisors (see below), whose sum is σ = 29562624. Its totient is φ = 14701920.

The previous prime is 21498143. The next prime is 21498163. The reversal of 21498155 is 55189412.

It is not a de Polignac number, because 21498155 - 2⁶ = 21498091 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19160 + ... + 20250.

It is an arithmetic number, because the mean of its divisors is an integer number (1847664).

Almost surely, 2^21498155 is an apocalyptic number.

21498155 is a deficient number, since it is larger than the sum of its proper divisors (8064469).

21498155 is a wasteful number, since it uses less digits than its factorization.

21498155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666.

The product of its digits is 14400, while the sum is 35.

The square root of 21498155 is about 4636.6102920129. The cubic root of 21498155 is about 278.0569341494.

The spelling of 21498155 in words is "twenty-one million, four hundred ninety-eight thousand, one hundred fifty-five".