400581538661 has 8 divisors (see below), whose sum is σ = 401920995840. Its totient is φ = 399244249008.

The previous prime is 400581538639. The next prime is 400581538673. The reversal of 400581538661 is 166835185004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400581538661 - 2²² = 400577344357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400581538061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171221 + ... + 911306.

It is an arithmetic number, because the mean of its divisors is an integer number (50240124480).

Almost surely, 2^400581538661 is an apocalyptic number.

It is an amenable number.

400581538661 is a deficient number, since it is larger than the sum of its proper divisors (1339457179).

400581538661 is a wasteful number, since it uses less digits than its factorization.

400581538661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1083763.

The product of its (nonzero) digits is 691200, while the sum is 47.

The spelling of 400581538661 in words is "four hundred billion, five hundred eighty-one million, five hundred thirty-eight thousand, six hundred sixty-one".