40253721661 has 4 divisors (see below), whose sum is σ = 41110183872. Its totient is φ = 39397259452.

The previous prime is 40253721647. The next prime is 40253721667. The reversal of 40253721661 is 16612735204.

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 a cyclic number.

It is not a de Polignac number, because 40253721661 - 2⁷ = 40253721533 is a prime.

It is a super-2 number, since 2×40253721661² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40253721661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40253721667) 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, 428231035 + ... + 428231128.

It is an arithmetic number, because the mean of its divisors is an integer number (10277545968).

Almost surely, 2^40253721661 is an apocalyptic number.

It is an amenable number.

40253721661 is a deficient number, since it is larger than the sum of its proper divisors (856462211).

40253721661 is an equidigital number, since it uses as much as digits as its factorization.

40253721661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856462210.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 40253721661 in words is "forty billion, two hundred fifty-three million, seven hundred twenty-one thousand, six hundred sixty-one".