61401071721 has 16 divisors (see below), whose sum is σ = 89346970368. Its totient is φ = 37197637200.

The previous prime is 61401071687. The next prime is 61401071759. The reversal of 61401071721 is 12717010416.

It is not a de Polignac number, because 61401071721 - 2¹¹ = 61401069673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61401072721) 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, 295695 + ... + 458516.

It is an arithmetic number, because the mean of its divisors is an integer number (5584185648).

Almost surely, 2^61401071721 is an apocalyptic number.

It is an amenable number.

61401071721 is a deficient number, since it is larger than the sum of its proper divisors (27945898647).

61401071721 is a wasteful number, since it uses less digits than its factorization.

61401071721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756692.

The product of its (nonzero) digits is 2352, while the sum is 30.

The spelling of 61401071721 in words is "sixty-one billion, four hundred one million, seventy-one thousand, seven hundred twenty-one".