261211604 has 24 divisors (see below), whose sum is σ = 465413760. Its totient is φ = 128254464.

The previous prime is 261211589. The next prime is 261211609. The reversal of 261211604 is 406112162.

It is a self number, because there is not a number n which added to its sum of digits gives 261211604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261211609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58847 + ... + 63129.

It is an arithmetic number, because the mean of its divisors is an integer number (19392240).

Almost surely, 2^261211604 is an apocalyptic number.

It is an amenable number.

261211604 is a deficient number, since it is larger than the sum of its proper divisors (204202156).

261211604 is a wasteful number, since it uses less digits than its factorization.

261211604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4559 (or 4557 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 261211604 is about 16162.0420739460. The cubic root of 261211604 is about 639.2403127922.

Adding to 261211604 its reverse (406112162), we get a palindrome (667323766).

The spelling of 261211604 in words is "two hundred sixty-one million, two hundred eleven thousand, six hundred four".