21698654 has 4 divisors (see below), whose sum is σ = 32547984. Its totient is φ = 10849326.

The previous prime is 21698639. The next prime is 21698657. The reversal of 21698654 is 45689612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21698657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5424662 + ... + 5424665.

It is an arithmetic number, because the mean of its divisors is an integer number (8136996).

Almost surely, 2^21698654 is an apocalyptic number.

21698654 is a deficient number, since it is larger than the sum of its proper divisors (10849330).

21698654 is a wasteful number, since it uses less digits than its factorization.

21698654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10849329.

The product of its digits is 103680, while the sum is 41.

The square root of 21698654 is about 4658.1814047974. The cubic root of 21698654 is about 278.9186780970.

The spelling of 21698654 in words is "twenty-one million, six hundred ninety-eight thousand, six hundred fifty-four".