8021561262 has 64 divisors (see below), whose sum is σ = 18861292800. Its totient is φ = 2242195200.

The previous prime is 8021561243. The next prime is 8021561263. The reversal of 8021561262 is 2621651208.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8021561263) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1723114 + ... + 1727762.

It is an arithmetic number, because the mean of its divisors is an integer number (294707700).

Almost surely, 2^8021561262 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8021561262, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9430646400).

8021561262 is an abundant number, since it is smaller than the sum of its proper divisors (10839731538).

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

8021561262 is a wasteful number, since it uses less digits than its factorization.

8021561262 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6689.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 8021561262 is about 89563.1691154349. The cubic root of 8021561262 is about 2001.7951600514.

The spelling of 8021561262 in words is "eight billion, twenty-one million, five hundred sixty-one thousand, two hundred sixty-two".