20870842 has 16 divisors (see below), whose sum is σ = 31815432. Its totient is φ = 10267200.

The previous prime is 20870813. The next prime is 20870869. The reversal of 20870842 is 24807802.

It can be written as a sum of positive squares in 4 ways, for example, as 19527561 + 1343281 = 4419^2 + 1159^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55768 + ... + 56140.

Almost surely, 2^20870842 is an apocalyptic number.

20870842 is a deficient number, since it is larger than the sum of its proper divisors (10944590).

20870842 is a wasteful number, since it uses less digits than its factorization.

20870842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 20870842 is about 4568.4616666883. The cubic root of 20870842 is about 275.3256395880.

It can be divided in two parts, 20870 and 842, that added together give a palindrome (21712).

The spelling of 20870842 in words is "twenty million, eight hundred seventy thousand, eight hundred forty-two".