66961489 has 15 divisors (see below), whose sum is σ = 78587657. Its totient is φ = 57051876.

The previous prime is 66961471. The next prime is 66961507. The reversal of 66961489 is 98416966.

The square root of 66961489 is 8183.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (66961471) and next prime (66961507).

It is not a de Polignac number, because 66961489 - 2⁷ = 66961361 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (66961409) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 400884 + ... + 401050.

Almost surely, 2^66961489 is an apocalyptic number.

66961489 is the 8183-rd square number.

66961489 is the 4092-nd centered octagonal number.

It is an amenable number.

66961489 is a deficient number, since it is larger than the sum of its proper divisors (11626168).

66961489 is an frugal number, since it uses more digits than its factorization.

66961489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 174 counting only the distinct ones).

The product of its digits is 559872, while the sum is 49.

The cubic root of 66961489 is about 406.0769770809.

Multiplying 66961489 by its sum of digits (49), we get a square (3281112961 = 57281²).

66961489 divided by its sum of digits (49) gives a square (1366561 = 1169²).

The spelling of 66961489 in words is "sixty-six million, nine hundred sixty-one thousand, four hundred eighty-nine".