1220776261 has 16 divisors (see below), whose sum is σ = 1289203200. Its totient is φ = 1154563200.

The previous prime is 1220776253. The next prime is 1220776279. The reversal of 1220776261 is 1626770221.

It is a cyclic number.

It is not a de Polignac number, because 1220776261 - 2³ = 1220776253 is a prime.

It is a super-2 number, since 2×1220776261² = 2980589358842280242, which 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 (1220776231) 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, 260265 + ... + 264913.

It is an arithmetic number, because the mean of its divisors is an integer number (80575200).

Almost surely, 2^1220776261 is an apocalyptic number.

It is an amenable number.

1220776261 is a deficient number, since it is larger than the sum of its proper divisors (68426939).

1220776261 is a wasteful number, since it uses less digits than its factorization.

1220776261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4884.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 1220776261 is about 34939.6087699905. The cubic root of 1220776261 is about 1068.7563099567.

The spelling of 1220776261 in words is "one billion, two hundred twenty million, seven hundred seventy-six thousand, two hundred sixty-one".