8400261981 has 4 divisors (see below), whose sum is σ = 11200349312. Its totient is φ = 5600174652.

The previous prime is 8400261973. The next prime is 8400262069. The reversal of 8400261981 is 1891620048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8400261981 - 2³ = 8400261973 is a prime.

It is a super-2 number, since 2×8400261981² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8400261911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1400043661 + ... + 1400043666.

It is an arithmetic number, because the mean of its divisors is an integer number (2800087328).

Almost surely, 2^8400261981 is an apocalyptic number.

It is an amenable number.

8400261981 is a deficient number, since it is larger than the sum of its proper divisors (2800087331).

8400261981 is a wasteful number, since it uses less digits than its factorization.

8400261981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2800087330.

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 8400261981 is about 91652.9431115008. The cubic root of 8400261981 is about 2032.8138464683.

The spelling of 8400261981 in words is "eight billion, four hundred million, two hundred sixty-one thousand, nine hundred eighty-one".