61521018 has 32 divisors (see below), whose sum is σ = 132947136. Its totient is φ = 18866688.

The previous prime is 61520999. The next prime is 61521029. The reversal of 61521018 is 81012516.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25930 + ... + 28202.

It is an arithmetic number, because the mean of its divisors is an integer number (4154598).

Almost surely, 2^61521018 is an apocalyptic number.

61521018 is an abundant number, since it is smaller than the sum of its proper divisors (71426118).

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

61521018 is a wasteful number, since it uses less digits than its factorization.

61521018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2638.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 61521018 is about 7843.5335149408. The cubic root of 61521018 is about 394.7672997822.

It can be divided in two parts, 615 and 21018, that multiplied together give a triangular number (12926070 = T₅₀₈₄).

The spelling of 61521018 in words is "sixty-one million, five hundred twenty-one thousand, eighteen".