61261209 has 6 divisors (see below), whose sum is σ = 88488426. Its totient is φ = 40840800.

The previous prime is 61261199. The next prime is 61261219. The reversal of 61261209 is 90216216.

It is an interprime number because it is at equal distance from previous prime (61261199) and next prime (61261219).

It can be written as a sum of positive squares in only one way, i.e., 38192400 + 23068809 = 6180^2 + 4803^2 .

It is not a de Polignac number, because 61261209 - 2¹⁷ = 61130137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61261219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3403392 + ... + 3403409.

It is an arithmetic number, because the mean of its divisors is an integer number (14748071).

Almost surely, 2^61261209 is an apocalyptic number.

It is an amenable number.

61261209 is a deficient number, since it is larger than the sum of its proper divisors (27227217).

61261209 is a wasteful number, since it uses less digits than its factorization.

61261209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6806807 (or 6806804 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 61261209 is about 7826.9540052309. The cubic root of 61261209 is about 394.2108026171.

The spelling of 61261209 in words is "sixty-one million, two hundred sixty-one thousand, two hundred nine".