70661581 has 2 divisors, whose sum is σ = 70661582. Its totient is φ = 70661580.

The previous prime is 70661557. The next prime is 70661621. The reversal of 70661581 is 18516607.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38068900 + 32592681 = 6170^2 + 5709^2 .

It is a cyclic number.

It is not a de Polignac number, because 70661581 - 2¹⁹ = 70137293 is a prime.

It is a super-2 number, since 2×70661581² = 9986118058839122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70667581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35330790 + 35330791.

It is an arithmetic number, because the mean of its divisors is an integer number (35330791).

Almost surely, 2^70661581 is an apocalyptic number.

It is an amenable number.

70661581 is a deficient number, since it is larger than the sum of its proper divisors (1).

70661581 is an equidigital number, since it uses as much as digits as its factorization.

70661581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 70661581 is about 8406.0443134687. The cubic root of 70661581 is about 413.4228248098.

The spelling of 70661581 in words is "seventy million, six hundred sixty-one thousand, five hundred eighty-one".