16040421561 has 16 divisors (see below), whose sum is σ = 21513728960. Its totient is φ = 10630509120.

The previous prime is 16040421493. The next prime is 16040421577. The reversal of 16040421561 is 16512404061.

It is not a de Polignac number, because 16040421561 - 2¹⁷ = 16040290489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16040421581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 436446 + ... + 471768.

It is an arithmetic number, because the mean of its divisors is an integer number (1344608060).

Almost surely, 2^16040421561 is an apocalyptic number.

It is an amenable number.

16040421561 is a deficient number, since it is larger than the sum of its proper divisors (5473307399).

16040421561 is a wasteful number, since it uses less digits than its factorization.

16040421561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36216.

The product of its (nonzero) digits is 5760, while the sum is 30.

The spelling of 16040421561 in words is "sixteen billion, forty million, four hundred twenty-one thousand, five hundred sixty-one".