20501670 has 64 divisors (see below), whose sum is σ = 56609280. Its totient is φ = 4654848.

The previous prime is 20501653. The next prime is 20501699. The reversal of 20501670 is 7610502.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48721 + ... + 49139.

It is an arithmetic number, because the mean of its divisors is an integer number (884520).

Almost surely, 2^20501670 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20501670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28304640).

20501670 is an abundant number, since it is smaller than the sum of its proper divisors (36107610).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20501670 is a wasteful number, since it uses less digits than its factorization.

20501670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 20501670 is about 4527.8769859615. The cubic root of 20501670 is about 273.6926153147.

The spelling of 20501670 in words is "twenty million, five hundred one thousand, six hundred seventy".