261099604 has 6 divisors (see below), whose sum is σ = 456924314. Its totient is φ = 130549800.

The previous prime is 261099599. The next prime is 261099649. The reversal of 261099604 is 406990162.

It can be written as a sum of positive squares in only one way, i.e., 259532100 + 1567504 = 16110^2 + 1252^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32637447 + ... + 32637454.

Almost surely, 2^261099604 is an apocalyptic number.

It is an amenable number.

261099604 is a deficient number, since it is larger than the sum of its proper divisors (195824710).

261099604 is a wasteful number, since it uses less digits than its factorization.

261099604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65274905 (or 65274903 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 261099604 is about 16158.5767937650. The cubic root of 261099604 is about 639.1489371298.

The spelling of 261099604 in words is "two hundred sixty-one million, ninety-nine thousand, six hundred four".