21347655 has 16 divisors (see below), whose sum is σ = 39035904. Its totient is φ = 9758880.

The previous prime is 21347653. The next prime is 21347701. The reversal of 21347655 is 55674312.

It is not a de Polignac number, because 21347655 - 2¹ = 21347653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21347653) 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, 101551 + ... + 101760.

It is an arithmetic number, because the mean of its divisors is an integer number (2439744).

Almost surely, 2^21347655 is an apocalyptic number.

21347655 is a deficient number, since it is larger than the sum of its proper divisors (17688249).

21347655 is a wasteful number, since it uses less digits than its factorization.

21347655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203326.

The product of its digits is 25200, while the sum is 33.

The square root of 21347655 is about 4620.3522592980. The cubic root of 21347655 is about 277.4065589138.

It can be divided in two parts, 213476 and 55, that added together give a triangular number (213531 = T₆₅₃).

The spelling of 21347655 in words is "twenty-one million, three hundred forty-seven thousand, six hundred fifty-five".