16720251 has 8 divisors (see below), whose sum is σ = 22837584. Its totient is φ = 10874880.

The previous prime is 16720243. The next prime is 16720279. The reversal of 16720251 is 15202761.

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

It is not a de Polignac number, because 16720251 - 2³ = 16720243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16725251) 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, 67846 + ... + 68091.

It is an arithmetic number, because the mean of its divisors is an integer number (2854698).

Almost surely, 2^16720251 is an apocalyptic number.

16720251 is a deficient number, since it is larger than the sum of its proper divisors (6117333).

16720251 is a wasteful number, since it uses less digits than its factorization.

16720251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135981.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 16720251 is about 4089.0403519652. The cubic root of 16720251 is about 255.7099324825.

The spelling of 16720251 in words is "sixteen million, seven hundred twenty thousand, two hundred fifty-one".