21702154 has 4 divisors (see below), whose sum is σ = 32553234. Its totient is φ = 10851076.

The previous prime is 21702103. The next prime is 21702157. The reversal of 21702154 is 45120712.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 19158129 + 2544025 = 4377^2 + 1595^2 .

It is not an unprimeable number, because it can be changed into a prime (21702157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5425537 + ... + 5425540.

Almost surely, 2^21702154 is an apocalyptic number.

21702154 is a deficient number, since it is larger than the sum of its proper divisors (10851080).

21702154 is a wasteful number, since it uses less digits than its factorization.

21702154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10851079.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21702154 is about 4658.5570727426. The cubic root of 21702154 is about 278.9336738488.

Adding to 21702154 its reverse (45120712), we get a palindrome (66822866).

The spelling of 21702154 in words is "twenty-one million, seven hundred two thousand, one hundred fifty-four".