1649987418781 has 32 divisors (see below), whose sum is σ = 1844469164160. Its totient is φ = 1465525281024.

The previous prime is 1649987418731. The next prime is 1649987418847. The reversal of 1649987418781 is 1878147899461.

It is a cyclic number.

It is not a de Polignac number, because 1649987418781 - 2²¹ = 1649985321629 is a prime.

It is a super-2 number, since 2×1649987418781² (a number of 25 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 (1649987418731) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135650206 + ... + 135662368.

It is an arithmetic number, because the mean of its divisors is an integer number (57639661380).

Almost surely, 2^{1649987418781} is an apocalyptic number.

It is an amenable number.

1649987418781 is a deficient number, since it is larger than the sum of its proper divisors (194481745379).

1649987418781 is a wasteful number, since it uses less digits than its factorization.

1649987418781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13405.

The product of its digits is 195084288, while the sum is 73.

The spelling of 1649987418781 in words is "one trillion, six hundred forty-nine billion, nine hundred eighty-seven million, four hundred eighteen thousand, seven hundred eighty-one".