21746545 has 8 divisors (see below), whose sum is σ = 27469440. Its totient is φ = 16481520.

The previous prime is 21746537. The next prime is 21746563. The reversal of 21746545 is 54564712.

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

It is not a de Polignac number, because 21746545 - 2³ = 21746537 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21746545.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114361 + ... + 114550.

It is an arithmetic number, because the mean of its divisors is an integer number (3433680).

Almost surely, 2^21746545 is an apocalyptic number.

It is an amenable number.

21746545 is a deficient number, since it is larger than the sum of its proper divisors (5722895).

21746545 is a wasteful number, since it uses less digits than its factorization.

21746545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228935.

The product of its digits is 33600, while the sum is 34.

The square root of 21746545 is about 4663.3190969523. The cubic root of 21746545 is about 279.1237273627.

It can be divided in two parts, 217 and 46545, that multiplied together give a triangular number (10100265 = T₄₄₉₄).

The spelling of 21746545 in words is "twenty-one million, seven hundred forty-six thousand, five hundred forty-five".