20021654 has 4 divisors (see below), whose sum is σ = 30032484. Its totient is φ = 10010826.

The previous prime is 20021641. The next prime is 20021663. The reversal of 20021654 is 45612002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45612002 = 2 ⋅22806001.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5005412 + ... + 5005415.

It is an arithmetic number, because the mean of its divisors is an integer number (7508121).

Almost surely, 2^20021654 is an apocalyptic number.

20021654 is a deficient number, since it is larger than the sum of its proper divisors (10010830).

20021654 is a wasteful number, since it uses less digits than its factorization.

20021654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10010829.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20021654 is about 4474.5562908516. The cubic root of 20021654 is about 271.5396896576.

Adding to 20021654 its reverse (45612002), we get a palindrome (65633656).

The spelling of 20021654 in words is "twenty million, twenty-one thousand, six hundred fifty-four".