261209211772 has 6 divisors (see below), whose sum is σ = 457116120608. Its totient is φ = 130604605884.

The previous prime is 261209211751. The next prime is 261209211779. The reversal of 261209211772 is 277112902162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261209211779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32651151468 + ... + 32651151475.

Almost surely, 2^261209211772 is an apocalyptic number.

It is an amenable number.

261209211772 is a deficient number, since it is larger than the sum of its proper divisors (195906908836).

261209211772 is a wasteful number, since it uses less digits than its factorization.

261209211772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65302302947 (or 65302302945 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 40.

The spelling of 261209211772 in words is "two hundred sixty-one billion, two hundred nine million, two hundred eleven thousand, seven hundred seventy-two".