61521019 has 24 divisors (see below), whose sum is σ = 74791296. Its totient is φ = 50400000.

The previous prime is 61520999. The next prime is 61521029. The reversal of 61521019 is 91012516.

It is not a de Polignac number, because 61521019 - 2⁷ = 61520891 is a prime.

It is a super-2 number, since 2×61521019² = 7569671557596722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61520984 and 61521002.

It is not an unprimeable number, because it can be changed into a prime (61521029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 153219 + ... + 153619.

It is an arithmetic number, because the mean of its divisors is an integer number (3116304).

Almost surely, 2^61521019 is an apocalyptic number.

61521019 is a deficient number, since it is larger than the sum of its proper divisors (13270277).

61521019 is a wasteful number, since it uses less digits than its factorization.

61521019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 61521019 is about 7843.5335786876. The cubic root of 61521019 is about 394.7673019212.

The spelling of 61521019 in words is "sixty-one million, five hundred twenty-one thousand, nineteen".