1266540061 has 32 divisors (see below), whose sum is σ = 1381847040. Its totient is φ = 1158537600.

The previous prime is 1266540031. The next prime is 1266540071. The reversal of 1266540061 is 1600456621.

It is a cyclic number.

It is not a de Polignac number, because 1266540061 - 2¹⁷ = 1266408989 is a prime.

It is a super-2 number, since 2×1266540061² = 3208247452235767442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266540031) 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, 9111730 + ... + 9111868.

It is an arithmetic number, because the mean of its divisors is an integer number (43182720).

Almost surely, 2^1266540061 is an apocalyptic number.

It is an amenable number.

1266540061 is a deficient number, since it is larger than the sum of its proper divisors (115306979).

1266540061 is a wasteful number, since it uses less digits than its factorization.

1266540061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1266540061 is about 35588.4821395912. The cubic root of 1266540061 is about 1081.9478055623.

Adding to 1266540061 its reverse (1600456621), we get a palindrome (2866996682).

The spelling of 1266540061 in words is "one billion, two hundred sixty-six million, five hundred forty thousand, sixty-one".