64121945 has 4 divisors (see below), whose sum is σ = 76946340. Its totient is φ = 51297552.

The previous prime is 64121879. The next prime is 64121957. The reversal of 64121945 is 54912146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54912146 = 2 ⋅27456073.

It can be written as a sum of positive squares in 2 ways, for example, as 35617024 + 28504921 = 5968^2 + 5339^2 .

It is a cyclic number.

It is not a de Polignac number, because 64121945 - 2⁸ = 64121689 is a prime.

It is a super-2 number, since 2×64121945² = 8223247661166050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6412190 + ... + 6412199.

It is an arithmetic number, because the mean of its divisors is an integer number (19236585).

Almost surely, 2^64121945 is an apocalyptic number.

It is an amenable number.

64121945 is a deficient number, since it is larger than the sum of its proper divisors (12824395).

64121945 is a wasteful number, since it uses less digits than its factorization.

64121945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12824394.

The product of its digits is 8640, while the sum is 32.

The square root of 64121945 is about 8007.6179354412. The cubic root of 64121945 is about 400.2538908978.

The spelling of 64121945 in words is "sixty-four million, one hundred twenty-one thousand, nine hundred forty-five".