1661258907 has 72 divisors (see below), whose sum is σ = 3143642112. Its totient is φ = 835077600.

The previous prime is 1661258891. The next prime is 1661258953. The reversal of 1661258907 is 7098521661.

1661258907 is a `hidden beast` number, since 1 + 6 + 61 + 2 + 589 + 0 + 7 = 666.

It is not a de Polignac number, because 1661258907 - 2⁴ = 1661258891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661258107) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 144858 + ... + 155904.

It is an arithmetic number, because the mean of its divisors is an integer number (43661696).

Almost surely, 2^1661258907 is an apocalyptic number.

1661258907 is a deficient number, since it is larger than the sum of its proper divisors (1482383205).

1661258907 is a wasteful number, since it uses less digits than its factorization.

1661258907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11109 (or 11099 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1661258907 is about 40758.5439754661. The cubic root of 1661258907 is about 1184.3473904838.

The spelling of 1661258907 in words is "one billion, six hundred sixty-one million, two hundred fifty-eight thousand, nine hundred seven".