20858720402 has 16 divisors (see below), whose sum is σ = 33767966232. Its totient is φ = 9606213120.

The previous prime is 20858720329. The next prime is 20858720417. The reversal of 20858720402 is 20402785802.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 13691574121 + 7167146281 = 117011^2 + 84659^2 .

It is a super-2 number, since 2×20858720402² (a number of 21 digits) contains 22 as substring.

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, 858143 + ... + 882114.

Almost surely, 2^20858720402 is an apocalyptic number.

20858720402 is a deficient number, since it is larger than the sum of its proper divisors (12909245830).

20858720402 is a wasteful number, since it uses less digits than its factorization.

20858720402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740733.

The product of its (nonzero) digits is 71680, while the sum is 38.

The spelling of 20858720402 in words is "twenty billion, eight hundred fifty-eight million, seven hundred twenty thousand, four hundred two".