61897905 has 64 divisors (see below), whose sum is σ = 115395840. Its totient is φ = 31449600.

The previous prime is 61897879. The next prime is 61897907. The reversal of 61897905 is 50979816.

61897905 = 828² + 829² + ... + 909².

It is not a de Polignac number, because 61897905 - 2⁵ = 61897873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61897907) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 293250 + ... + 293460.

It is an arithmetic number, because the mean of its divisors is an integer number (1803060).

Almost surely, 2^61897905 is an apocalyptic number.

It is an amenable number.

61897905 is a deficient number, since it is larger than the sum of its proper divisors (53497935).

61897905 is a wasteful number, since it uses less digits than its factorization.

61897905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319 (or 313 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 61897905 is about 7867.5221639345. The cubic root of 61897905 is about 395.5717937927.

The spelling of 61897905 in words is "sixty-one million, eight hundred ninety-seven thousand, nine hundred five".