261535064657772 has 24 divisors (see below), whose sum is σ = 610248862555696. Its totient is φ = 87178300835328.

The previous prime is 261535064657761. The next prime is 261535064657807. The reversal of 261535064657772 is 277756460535162.

261535064657772 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16647888 + ... + 28288200.

Almost surely, 2^{261535064657772} is an apocalyptic number.

It is an amenable number.

261535064657772 is an abundant number, since it is smaller than the sum of its proper divisors (348713797897924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261535064657772 is a wasteful number, since it uses less digits than its factorization.

261535064657772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13512657 (or 13512655 counting only the distinct ones).

The product of its (nonzero) digits is 444528000, while the sum is 66.

The spelling of 261535064657772 in words is "two hundred sixty-one trillion, five hundred thirty-five billion, sixty-four million, six hundred fifty-seven thousand, seven hundred seventy-two".