61261515 has 84 divisors (see below), whose sum is σ = 128589264. Its totient is φ = 28005264.

The previous prime is 61261513. The next prime is 61261537. The reversal of 61261515 is 51516216.

It is a happy number.

It is not a de Polignac number, because 61261515 - 2¹ = 61261513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

Its product of digits (1800) is a multiple of the sum of its prime divisors (15).

It is not an unprimeable number, because it can be changed into a prime (61261511) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 8751642 + ... + 8751648.

Almost surely, 2^61261515 is an apocalyptic number.

61261515 is an abundant number, since it is smaller than the sum of its proper divisors (67327749).

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

61261515 is an frugal number, since it uses more digits than its factorization.

61261515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58 (or 15 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 61261515 is about 7826.9735530408. The cubic root of 61261515 is about 394.2114589776.

It can be divided in two parts, 61261 and 515, that added together give a triangular number (61776 = T₃₅₁).

The spelling of 61261515 in words is "sixty-one million, two hundred sixty-one thousand, five hundred fifteen".