71661970 has 32 divisors (see below), whose sum is σ = 140282928. Its totient is φ = 26247168.

The previous prime is 71661943. The next prime is 71661979. The reversal of 71661970 is 7916617.

It can be written as a sum of positive squares in 8 ways, for example, as 63059481 + 8602489 = 7941^2 + 2933^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is not an unprimeable number, because it can be changed into a prime (71661979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 594 + ... + 11986.

Almost surely, 2^71661970 is an apocalyptic number.

71661970 is a deficient number, since it is larger than the sum of its proper divisors (68620958).

71661970 is a wasteful number, since it uses less digits than its factorization.

71661970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11454.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 71661970 is about 8465.3393316512. The cubic root of 71661970 is about 415.3646961096.

The spelling of 71661970 in words is "seventy-one million, six hundred sixty-one thousand, nine hundred seventy".