82137781 has 16 divisors (see below), whose sum is σ = 91744128. Its totient is φ = 72907200.

The previous prime is 82137767. The next prime is 82137787. The reversal of 82137781 is 18773128.

It is not a de Polignac number, because 82137781 - 2¹⁷ = 82006709 is a prime.

It is a super-2 number, since 2×82137781² = 13493230135207922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 82137781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82137787) 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, 111691 + ... + 112423.

It is an arithmetic number, because the mean of its divisors is an integer number (5734008).

Almost surely, 2^82137781 is an apocalyptic number.

It is an amenable number.

82137781 is a deficient number, since it is larger than the sum of its proper divisors (9606347).

82137781 is a wasteful number, since it uses less digits than its factorization.

82137781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972.

The product of its digits is 18816, while the sum is 37.

The square root of 82137781 is about 9062.9896281525. The cubic root of 82137781 is about 434.6913404697.

The spelling of 82137781 in words is "eighty-two million, one hundred thirty-seven thousand, seven hundred eighty-one".