20510742 has 64 divisors (see below), whose sum is σ = 49319424. Its totient is φ = 5564160.

The previous prime is 20510729. The next prime is 20510759. The reversal of 20510742 is 24701502.

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, 73908 + ... + 74184.

It is an arithmetic number, because the mean of its divisors is an integer number (770616).

Almost surely, 2^20510742 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20510742, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24659712).

20510742 is an abundant number, since it is smaller than the sum of its proper divisors (28808682).

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

20510742 is a wasteful number, since it uses less digits than its factorization.

20510742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 20510742 is about 4528.8786691630. The cubic root of 20510742 is about 273.7329790714.

The spelling of 20510742 in words is "twenty million, five hundred ten thousand, seven hundred forty-two".