61740437391 has 12 divisors (see below), whose sum is σ = 89202284080. Its totient is φ = 41150298240.

The previous prime is 61740437387. The next prime is 61740437411. The reversal of 61740437391 is 19373404716.

61740437391 is a `hidden beast` number, since 61 + 74 + 0 + 437 + 3 + 91 = 666.

It is not a de Polignac number, because 61740437391 - 2² = 61740437387 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 (61740437321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 793555 + ... + 867876.

Almost surely, 2^61740437391 is an apocalyptic number.

61740437391 is a deficient number, since it is larger than the sum of its proper divisors (27461846689).

61740437391 is a wasteful number, since it uses less digits than its factorization.

61740437391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665566 (or 1665563 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The spelling of 61740437391 in words is "sixty-one billion, seven hundred forty million, four hundred thirty-seven thousand, three hundred ninety-one".