43640506581421 has 8 divisors (see below), whose sum is σ = 45538006872960. Its totient is φ = 41743013536752.

The previous prime is 43640506581409. The next prime is 43640506581437. The reversal of 43640506581421 is 12418560504634.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43640506581421 is a prime.

It is a super-2 number, since 2×43640506581421² (a number of 28 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 (43640506581491) 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, 13108515 + ... + 16097023.

It is an arithmetic number, because the mean of its divisors is an integer number (5692250859120).

Almost surely, 2^{43640506581421} is an apocalyptic number.

It is an amenable number.

43640506581421 is a deficient number, since it is larger than the sum of its proper divisors (1897500291539).

43640506581421 is a wasteful number, since it uses less digits than its factorization.

43640506581421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3623435.

The product of its (nonzero) digits is 2764800, while the sum is 49.

The spelling of 43640506581421 in words is "forty-three trillion, six hundred forty billion, five hundred six million, five hundred eighty-one thousand, four hundred twenty-one".