20619997 has 8 divisors (see below), whose sum is σ = 22982400. Its totient is φ = 18385344.

The previous prime is 20619979. The next prime is 20620003. The reversal of 20619997 is 79991602.

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

It is a cyclic number.

It is not a de Polignac number, because 20619997 - 2¹⁹ = 20095709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20619917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31597 + ... + 32242.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^20619997 is an apocalyptic number.

It is an amenable number.

20619997 is a deficient number, since it is larger than the sum of its proper divisors (2362403).

20619997 is a wasteful number, since it uses less digits than its factorization.

20619997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63875.

The product of its (nonzero) digits is 61236, while the sum is 43.

The square root of 20619997 is about 4540.9246855679. The cubic root of 20619997 is about 274.2181516974.

The spelling of 20619997 in words is "twenty million, six hundred nineteen thousand, nine hundred ninety-seven".