61515740 has 96 divisors (see below), whose sum is σ = 153849024. Its totient is φ = 20367360.

The previous prime is 61515737. The next prime is 61515743. The reversal of 61515740 is 4751516.

It is an interprime number because it is at equal distance from previous prime (61515737) and next prime (61515743).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61515743) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391742 + ... + 391898.

It is an arithmetic number, because the mean of its divisors is an integer number (1602594).

Almost surely, 2^61515740 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61515740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76924512).

61515740 is an abundant number, since it is smaller than the sum of its proper divisors (92333284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61515740 is a wasteful number, since it uses less digits than its factorization.

61515740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 61515740 is about 7843.1970522230. The cubic root of 61515740 is about 394.7560101912.

The spelling of 61515740 in words is "sixty-one million, five hundred fifteen thousand, seven hundred forty".