1242090189081 has 81 divisors (see below), whose sum is σ = 2118945498111. Its totient is φ = 699080082624.

The previous prime is 1242090189061. The next prime is 1242090189083. The reversal of 1242090189081 is 1809810902421.

The square root of 1242090189081 is 1114491.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 705070899225 + 537019289856 = 839685^2 + 732816^2 .

It is not a de Polignac number, because 1242090189081 - 2⁷ = 1242090188953 is a prime.

It is a super-3 number, since 3×1242090189081³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (1242090189083) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1708514340 + ... + 1708515066.

Almost surely, 2^{1242090189081} is an apocalyptic number.

1242090189081 is the 1114491-st square number.

1242090189081 is the 557246-th centered octagonal number.

It is an amenable number.

1242090189081 is a deficient number, since it is larger than the sum of its proper divisors (876855309030).

1242090189081 is an frugal number, since it uses more digits than its factorization.

1242090189081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The spelling of 1242090189081 in words is "one trillion, two hundred forty-two billion, ninety million, one hundred eighty-nine thousand, eighty-one".