61759981 has 4 divisors (see below), whose sum is σ = 63266364. Its totient is φ = 60253600.

The previous prime is 61759969. The next prime is 61760009. The reversal of 61759981 is 18995716.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13942756 + 47817225 = 3734^2 + 6915^2 .

It is not a de Polignac number, because 61759981 - 2⁵ = 61759949 is a prime.

It is a super-2 number, since 2×61759981² = 7628590506240722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61759921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 753130 + ... + 753211.

It is an arithmetic number, because the mean of its divisors is an integer number (15816591).

Almost surely, 2^61759981 is an apocalyptic number.

It is an amenable number.

61759981 is a deficient number, since it is larger than the sum of its proper divisors (1506383).

61759981 is a wasteful number, since it uses less digits than its factorization.

61759981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506382.

The product of its digits is 136080, while the sum is 46.

The square root of 61759981 is about 7858.7518729121. The cubic root of 61759981 is about 395.2777643587.

The spelling of 61759981 in words is "sixty-one million, seven hundred fifty-nine thousand, nine hundred eighty-one".